Favorite happy songs get 175 plays. The sad ones get 800.

Lex Fridman opens with a number that does not match what people say they want. Those whose favorite songs are happy ones play them on a playlist about 175 times. Those who love sad music play theirs about 800, and they report feeling connected to the sublime. Almost anyone, asked cold, will say they want to be happy. Behavior on the playlist is something else: people return, over and over, to melodies that hurt, and they experience that return as enjoyment, even as something close to sacred.

Susan Cain spent years on both halves of that puzzle. *Quiet* argued for the roughly half of the world that is introverted, the people who, two hours into a party they are actually enjoying, suddenly wish they could teleport home. *Bittersweet* asked how sorrow and longing make a person whole. On this episode the two books sit in one room: how you budget your energy, and how you live with the ache for something you cannot quite hold.

Cain’s website line is the start of a definition: she prefers listening to talking, reading to socializing, cozy chats to group settings. The cleaner test, she says, is energy. Imagine a party you are really enjoying, in your favorite place, with people you actually like. An extrovert in that room feels charged and starts asking where the afterparty is. An introvert, no matter how good a time they are having or how socially skilled they are, hits a moment of wanting to teleport home. The shorter the time from the door to that moment, the more introverted you are. Flip it and an extrovert stuck alone on an absorbing memo goes stir-crazy sooner.

It is not about what you are good at. It is neurobiology: how the nervous system handles stimulation. Introverts are in equilibrium when fewer inputs are coming in, which is why one close friend beats a room of strangers. Extroverts need more stimulation; without it they go listless and sluggish. The same quiet room that soothes one person makes the other panic. Fridman asks the obvious objection: maybe you want to be alone because everyone around you is an asshole. Cain’s answer is to hold the variables constant. Keep the people decent, then see.

A practical self-test is a free Saturday with no professional or social obligations. Who would you spend it with, how many of them, doing what? After years on the topic she finds that most people already know, once they are honest with themselves. The battery metaphor is close enough: introverts drain and recharge. Complexity sits on top of that. You can hate being “on” in a crowd and still get lonely alone. What you may want is two people you know well. The pandemic, for Cain, was not hard on that axis; she lives with her husband and children, which counted as a full social life in the house while she worked.

Fridman has watched people swear they are drained by humans, then become the life of the party. Cain hears from those people constantly. Humans are too complex to trap in one parameter, she warns, but two common stories fit. Some are ambiverts, in the middle of the spectrum, and a party pulls out the more extroverted side. Others are introverts who have learned the skills of a pseudo-extrovert and can call the act up when they need it. She may have heard from more of those people than anyone else on the planet, because they come to tell her that the face they present is not what they feel.

The West built a picture of success that looks like an extrovert. Imagine a leader and you usually get outgoing traits, which is a strong incentive to fake it if you want to hang with the team. Cain has also seen the other path: introverts who do not fake it, who find ways to lead on their own strengths. Doug Conant, CEO of Campbell Soup for years, is very introverted and, by his own description, quite shy. When he arrived, employee engagement sat at the bottom of the Fortune 500. Ten years later it sat at the top. He was not out schmoozing. He found the people who had actually contributed and wrote them personal letters of thanks. People carried those letters. Over a decade he wrote 30,000 of them. He still left his comfort zone when he had to. The base was care, not performance.

Before she was a writer, Cain spent seven years as a corporate lawyer. The only thing she misses is hanging around the office. Some of the funniest hours of her life were midnight with colleagues. Those offices were a long hallway of private rooms, like a dorm: plenty of privacy, and you could roam when you wanted. A door wide open, half ajar, or barely cracked was a signal. Roaming meant you were open to being interrupted. That architecture is the opposite of the open-plan fad, and she thinks the post-pandemic office is still trying to relearn it.

Remote meetings are easy to overfill because the cost of adding one more person is almost zero, so introvert batteries empty faster. Cain’s concrete explanation is the self-view. On video you can watch your own presentation the whole time; in a room you cannot, so you are freed of that extra cognitive load. You could turn the camera off, but then you feel you probably should keep it on, and the decision itself costs attention. People told her they actually enjoyed pandemic Zooms for a simpler reason: they were lonely. Sitting through empty talk is annoying, and they dialed in anyway.

Cain does her podcast interviews in person even when it is costly, because most conversations have chemistry. Under a boring work meeting, a team is still being built. Offices look like a line item from a capitalist view — why rent this much space? — and she thinks some of the value of being together does not fit that spreadsheet. There is also a third space: a coworking room or a café, other people around you, no need to interact, and they are very much there. She lived in Manhattan for seventeen years before children and loved the energy with the option of anonymity inside it.

Fridman fell in love with podcasts before video. His favorite interviews are still two people on microphones, the other voice in the ear, which he calls the ultimate intimacy. Cain still goes on Clubhouse, the audio-only social platform. None of her introvert alarms go off: nobody can see you, nobody is offended if you only listen, you speak when you want. At a physical party someone looks at you and the pressure to say something arrives. Audio also seems to make people more honest. She guesses it taps something ancient, stories around a fire, a tradition that started oral. They both admit you could see faces across a campfire, so the visual is fundamental too; the primal thing in audio remains a little unexplained. She hates the five-to-seven-minute TV hit her publisher trained her for, because you cannot tell the full truth in that slot. Fridman now requires three hours with CEOs. Two hours they can still market. In the third they break, joke, become human — or they cannot, which is also information.

Cain’s favorite Leonard Cohen song is “Famous Blue Raincoat.” It is a love triangle told as a letter from a man to the friend who has been with his wife. He calls him “my brother, my killer,” light and dark in the same breath, nothing only one thing. It opens at four in the morning at the end of December. Cain says that is not an accident: night going into day, December going into the year, both transitional. David Yaden, who studies psychedelics and consciousness at Johns Hopkins, has found that people in life’s transitions — career change, divorce, the end of life — often name those stretches as their most meaningful and spiritual. Cohen, she thinks, knew how to tap that place by instinct.

The year after Cohen died, his son Adam held a memorial in Montreal. Cain’s husband is not a fan and not a bittersweet type, but he told her she had to go. The family flew on a nothing Monday; the children missed school. At first she thought it was a mistake: she wanted Cohen, not covers. Then Damien Rice sang “Famous Blue Raincoat” and, at the end, added a riff she can only call a musical lamentation of the ages. The audience rose silently to its feet. It was one of the greatest moments of her life. Covers can carry a song further without leaving its spirit: Johnny Cash on Nine Inch Nails’ “Hurt,” Heart singing “Stairway to Heaven” at the Kennedy Center with the original artists and Barack Obama in the room.

Dan Reynolds of Imagine Dragons, one of the most-played bands in streaming, told Fridman that you have to feel the song every time or the crowd knows. People are good at detecting fakes. Reynolds has long struggled with depression; Cain sees a good human and a deep marriage grown from that pain, a couple who lean on each other when times are good and stay grateful for the precious stretch. The hard part of the job is the comedown: tens of thousands of people, love in the air, then ordinary life. A lot of musicians chase the rush with drugs. Cain’s version of communion is a letter from a reader describing what a page meant. She was not in the room, so there is no concert high, only the knowledge that it happened somewhere and she added a little. The danger of thousands of those letters is taking yourself as a special person. She tries to treat it as the same feeling she has on the other side, as a reader.

Gary Saul Morson, a Northwestern scholar of Tolstoy and Dostoevsky, thinks readers misread *Anna Karenina*. They take it as a brief for grand, tempestuous romances that may end in death or despair, intensity as the point. Morson says Tolstoy meant the opposite. The novel sets those storms beside couples living quietly day by day, and everyday life is the ideal, not the collision. Fridman asks whether the day-to-day has its own romance. Cain says yes. She almost never takes photos at the official gathering; she photographs ordinary scenes, because that is what she actually wants to remember. Fridman admits the same habit is bad for productivity. He has a company he has wanted to build for years and does not spend enough time on it, partly because he loves sitting in silence with the beauty of ordinary life.

Why go through hell to found a company if you already love everything? Sometimes, he says, you look at the mountains and long to go, even if it means leaving the tribe and doing something stupid. That is exploration. Cain hears the same source code she writes about: longing as the engine of creativity, always reaching for Eden, for something you want to arrive at or make. Pain into making is not only for artists. Everyone meets pain; at our best we live with it a while and turn it into something we find beautiful — a cake, or, after the pandemic, a surge of applications to medical and nursing school, after 9/11 a surge toward firefighting and teaching. At our worst we deny the pain and take it out on ourselves and other people. The fork is there.

Researchers in her book had people watch happy, sad, or bittersweet films, then take creativity tasks. The group that watched *Father of the Bride* — walking a daughter down the aisle, love plus the knowledge it ends — scored highest. Love and impermanence, she says, get us to our most beautiful state.

Terror-management studies prime people with death and watch what changes. One finding is more tribalism. In another, after the prime, people got a chance to put hot sauce on a meal their political opponents would eat, and they put on far too much. Cain spent time with people working on radical life extension. Asked how you feed everyone, where they live, whether conflict explodes, they point at terror-management theory and say fear of death *is* the conflict; remove it and conflict falls. Cain does not really buy it. You may be throwing out the baby with the bathwater. Finality might be a source of meaning and happiness in the human condition, not a bug.

She went to a conference expecting those questions to fill the days. The mood was closer to relief at being among people who had gotten past the quibbles. The working assumption was extend life first, then decide if that was wise — or, more exactly, certainty that it is wise. Fridman offers the biology: nature designs organisms to die so young brains can explore and adapt; the old get stubborn, and if they never leave, the system goes stale. Maybe it does not have to happen so soon. He is a snooze-button man: he thinks death is part of life, and on the actual bed he would mash snooze as many times as he could. A leading advocate at the conference told Cain the “death gives life meaning” story is one we invented because we had no choice. If you truly believe you could triumph, would you still tell it? She has been thinking about that ever since.

Cain writes some things more clearly than she can say them. Her relationship with her mother was complicated. Childhood was a Garden of Eden, intensely close. In adolescence she grew independent, with different religious and political views; her mother, because of her own vulnerabilities, reacted hard. There was a break so complete that holidays and phone calls continued and the relationship, in a real sense, was over. Eden was gone. Bereavement has a mourning process humans have thought about for thousands of years. This kind of loss has no process, because in your teens and twenties you will not admit you are mourning. For decades she could not answer the simplest question — where did her mother grow up — without embarrassing tears, so she steered the subject away.

Two things changed it. Six or seven years of writing a book about joy, sorrow, loss, and love brought her to terms with it. Then her mother developed Alzheimer’s. She has forgotten most things and is still the same person. Conversational lanes remain, and down those lanes is the woman Cain knew as a child: loving, connected, warm, sweet, funny. For decades she had wondered whether Eden had happened or been a child’s fantasy of a hard life she had not seen. Watching her mother now, she knows it was all true, because it is happening again. Fridman asks if she has returned. She would not say so. She is a different person and does not need her mother. The need for love is the same; the dependence of a ten-year-old is not, and that makes the whole experience different. Parents, she thinks, are the most powerful formative force there is.

In a college creative-writing class she tried a fictionalized version titled “The Most Passionate Love.” The teacher told her to put it in a drawer for thirty years; she was too close. She has now written it. Everyone, she believes, meets some form of the pain of separation and the desire for union — betrayal, bereavement, exile from a birth country. Hers was her mother. You spend the rest of your life on that puzzle. What you learn, growing older, is that the original love exists on a more general plane than the particular form you first knew. Freud is probably wrong in the details and was first to say early experience shapes us; the first taste of love strongly forms the perfect thing you keep reaching for. She can see it as a parent. Her children are teenagers. She had feared repeating her mother’s trouble with independence and does not feel that trouble in herself. Fridman jokes that the unseen problem is always elsewhere. She says she will find out in ten or twenty years.

Her parenting counsel from the bittersweet side is for children raised in relative comfort. They get the idea that real life is when things go well, and trouble is a detour off the main road. The missing lesson is that it is all the main road. On a countryside holiday the house sat next to a field with two donkeys the little boys loved, carrots every day. Then they realized they were leaving in two days and would never see the donkeys again, and they cried themselves to sleep. The usual parent lines — maybe we will come back, another family will feed them — did nothing. What worked was: goodbye is part of life, everyone has this feeling, you have had it, you will have it, you will feel better in a few days, and this is the way it is supposed to be, this is natural. They stopped crying when they stopped resisting.

Fridman mentions a *Yellowstone* scene: a father takes a son hunting, the boy pulls the trigger and grieves taking a life, and the father says everybody gets killed, that is nature, each of us included. We say people “pass away”; medically, a truck or a bacterium still takes you. Cain wrote a whole book arguing that this is how it is, and that the reality has an intense beauty you only reach by accepting it. A part of her still wants the magic wand. Watching a show about Thermopylae with her twelve-year-old, all valor and battlefield glory, she asked whether he wished for a world where you did not have to do all that just to live. He looked puzzled. No. To him the world was obviously structured that way, and he had a twelve-year-old’s admiration for the valor.

She thinks war and death are too deep in the source code, and she cannot get past wishing the code were different. Fridman talks about brain-computer interfaces, already-cyborg smartphones, consciousness maybe offloaded into machines that might be less obsessed with war — and still he wants even a superintelligence to have yin and yang, fear and sadness. Maybe sadness is a useful human invention, not a universal. Cain wrote the book because what she feels in sad music is what believers describe when they talk about God, an ultimate beauty she is not sure we can reach without that path. Science has early signs: the vagus nerve, which runs breathing and digestion, also fires when we see another being in distress, an impulse to make it stop, probably grown from having to answer an infant’s cry.

Asked the meaning of life, two answers arrive at once; she has been asking since she was four. The first is beauty. She does not know why it matters, only that it does, and that you know it when you see or hear it. It delivers a transcendence in which you are no longer purely in the self. In that state you have the temporary sensation that you could die, that the people you love could die, and it would be all right because there is something else. The second is the need to relieve other people’s psychic pain, to put less pain into the world. In an interview someone asked what she was longing for; she said she was at a way station where everything was as she wanted. An hour later a reader wrote about a long psychic struggle, and she immediately wished she could have made a life in which he never arrived there. Peace lasted an hour. Fridman quotes Hunter S. Thompson: for every moment of triumph, for every instance of beauty, many souls must be trampled. Very Thompson, she says, and you know how he ended. Her husband’s nickname is Gonzo, after the journalism in which the writer is inside the story. His name is Ken. She calls him Gonzo about ninety percent of the time.

Why the 800 plays? One reason is that a musician has expressed something for you without words and made it beautiful: you have been through this, so have I, so have a lot of people. Researchers showed slides of sad faces and almost nobody cared. Music of other negative emotions, martial music, did not produce the lift. Only sad music did. So the active ingredient is not negativity. It is sadness plus beauty, tapping what Cain calls the human source code: a spiritual longing, believer or atheist, for a place of perfect love, unity, and truth, plus an acute awareness that we are not there. Religions carry it as Mecca, Eden, Zion. Art carries it as Dorothy wanting somewhere over the rainbow, or Harry Potter entering the story at the exact moment he becomes an orphan, so he will spend his life longing for parents he cannot remember.

Fridman offers Ernest Becker and Jung: maybe the warm at the core is fear of death, and the perfect thing is immortality, a way past the cruelty that everything ends for no good reason. Cain knows the line from Gilgamesh on. She thinks it is not only that. It is also a longing for the lion to lie down with the lamb, for the universe’s calculus to change so life does not have to eat life. She admits the picture is modern; most of history is violence and glorified violence. It can still be a real desire. Fridman pushes: how many lions, how many lambs, what economic system, what government? You start from longing and still have to build a society, and you return to the question. The rules of the game are the longing in its purest form.

Is loneliness the ground of the human condition? Would we still connect if we stopped being lonely? Cain says the fundamental thing is longing for union, and it looks completely different on different people. For many, union is highly social; for others, almost not. Everyone needs some version. Fridman’s empirical lesson from relationships is that time deepens the bond, with people and with things, so his life is a series of long commitments. Cain has been hearing a lot about polyamory. She has no judgment. She knows she wants one person.

The deepest nature, she says, is longing for a state of perfect completeness you will never quite attain, with glimpses here and there that are among the best things that happen to us, suffused with sadness because they are not the full thing. Straight loss — betrayal, bereavement — is different and overwhelming. What you can come to, after enough time on earth, is that love is not only its particular form. Love is a state you can enter; the pain of losing person A can heal into a bigger river. Fridman cites a Louis C.K. bit: an older man tells him to stop moping after a breakup, because this is the best part. Real loss is forgetting. Feeling terrible is when you most intensely know what the person meant. Cain agrees it is a signpost toward what you actually want. Mystical strains of the big religions all point here. Rumi: the longing is the cure. Be thirsty. The good stuff is the wanting, not the having. Tell that to someone who just got dumped, Fridman says, and they will tell you to shut up. She knows. The lesson only works after you have stepped away from the excruciation. Realizing everyone is in the same condition is itself a kind of love, and Western individualism makes that love hard to say out loud even as behavior keeps showing it.

Cain dedicated *Bittersweet* to Leonard Cohen. She has loved him for decades with a crazy love she is only now beginning to understand. She ran a thought experiment: if he were alive and she could meet him, would she want to? She is not sure. He represents, for her, everything; she stops the sentence there. That is all right. People can put something into art that might not show up over coffee. He was an introvert. When *Quiet* came out he tweeted about it, a precious moment. He struggled with depression. The link is not simple: depression tracks high sensitivity; about 80 percent of highly sensitive people are introverts, not all introverts are highly sensitive, some sensitive people are extroverts. A Venn diagram, overlapping, not identical. Rates of depression among artists sit far above the average. Rates of early parental loss among successful artists are, she says, astronomical. Cohen lost his father at nine. His father made suits. His first creative act was to take one of his father’s bow ties, write a poem in his honor, and bury the poem and the tie in the backyard.

“Chelsea Hotel No. 2” is about a brief crossing with Janis Joplin: head on the unmade bed while limousines wait in the street, “you told me again you preferred handsome men, but for me you would make an exception,” “we are ugly, but we have the music.” Joplin later said publicly that he was lousy in bed. Cain hears a sadness in the blaze: two paths intersecting, the car already waiting, nobody thinking it would last. Cohen said some people are more inclined to say hello with their music; he was rather more valedictory. So many of the songs are partings, imperfections, a broken hallelujah. What is incredible is that he points all of it at transcendence — not pure sadness, sadness plus beauty. His favorite poet was García Lorca; he named a daughter Lorca. A Lorca poem made him realize the universe itself was aching, and the ache was all right, because that is how you embrace the sun and the moon.

If she could choose another medium, it would be singing. She is not a singer. She is fundamentally shy, so writing was the right road. Fridman says that, mathematically, she should not be a good public speaker. Lots of introverts are, she answers. On the lecture circuit almost every fellow speaker was an introvert: people who spent years inside an idea and then came out to talk about it. We imagine a showman. There is another style, more reflective, and audiences like that too. She used to be phobic. In law school, knowing she would be called on, she once vomited on the way to class. The method is desensitization in small doses. You do not start with TED. She started in a class for speaking anxiety where day one was stand up, say your name, sit down, victory. Next week, several people at the front so the spotlight was shared, a few questions about hometown and school, victory again. Then you ratchet up until successes accumulate. TED is different: a one-person theatrical show. You would know every word of a Broadway monologue, so she rehearses that way. At first it comes out wooden; once the words are internalized, emotion returns and you speak from the heart. The new fear is forgetting. In her last TED talk she did forget, walked to her notes, the audience kindly clapped, she went back to the light. They edit that out. The world does not end.

Advice for the young: do the thing you are dying to do, and keep a backup way to earn a living. The culture’s glamorous story is find what you love and risk everything. A lot of people cannot carry that risk, and the risk itself is cognitive load, so anxiety eats the heart you needed for the work. Get the backup in place, then do the thing. Fridman’s advice is the opposite. If he has a Plan B he will not try as hard on Plan A, and he will likely take the B. He works best with his back against the wall. Not knowing how to pay the rent is when he is free; a safe income lets him find a way to pay it that has no deep fulfillment. Cain is the reverse. She would be up at two in the morning worrying about money. A basic way to pay rent frees her heart for the work she loves. They converge: do what you love, then arrange the rest of life around your actual triggers. Knowing yourself beats any universal slogan.

Fridman ends with a line from Cain on highly sensitive introverts. They tend to be philosophical or spiritual rather than materialistic or hedonistic. They dislike small talk. They often call themselves creative or intuitive. They dream vividly and can recall the dreams. They love music, nature, art, and physical beauty. Their emotions run exceptionally strong — acute joy, also sorrow, melancholy, and fear. They process physical and emotional environments unusually deeply, and they notice what others miss: a shift in someone’s mood, a light bulb burning a touch too brightly. If you recognize yourself, she has spent two books saying that is not a defect. It is a configuration, with a cost, and with access other people do not get.

One more small human fact sits near the end of the talk. In law school a classmate’s friend visited for a weekend; the three of them had an amazing time; then a postcard arrived with an Oscar Wilde line Cain remembers as: there is no pain as intense as the sorrow of parting from someone to whom you have just been introduced. You have seen the sparkling version. Imagination fills in the rest to match what you most care about. Fridman compares it to the first spoon of ice cream, which is why you finish the tub. Alain de Botton regularly gives her that click of a thought she had never quite said, a generosity that makes her less lonely, even especially when the line is melancholy. Kerouac’s *On the Road*, which she has not read, is Fridman’s version of the same: forlorn rags of growing old, leaning forward to the next crazy venture, beauty and the passing of time in one breath. Her husband loves Hemingway’s *A Moveable Feast* for the group that coalesces and then loses a person and is never the same. That, she says, is the whole reason she wrote *Bittersweet*.