I came to hold both truths at once: I’d caused him deep and lasting harm, by leaving him. And also, I did not regret choosing a life that would not share a home with his anger.

When I say I held both truths, I mean that I lay with them, sleepless, in the dark.

In the midst of those newborn months, I had a book coming out. It would be published when the baby was three months old. I usually described it as a book about drinking, though honestly it was a book about the only thing I ever wrote about: the great emptiness inside, the space I’d tried to fill with booze and sex and love and recovery and now, perhaps, with motherhood. The book was getting a lot of attention, which made me queasy—and also, like an addict, eager for more.

Unless you say otherwise, people assume the end of a marriage involves an affair. So I am saying otherwise. This one did not. Just the mistake of two people believing they could make a life together, when in fact they couldn’t. Which is its own betrayal.

My parents’ marriage left me more allergic to affairs than to endings. But I knew there were people who felt otherwise—who believed the worst thing was giving up too soon.

I was certainly capable of infidelity—had inherited some version of my father’s capacity, even as I judged him for it. In the past, I’d cheated on two boyfriends—could still remember waking up in the beds of other men, trapped inside my own body like a rumpled, foul-smelling outfit I could not remove.

For me, cheating had been a way to avoid the work of either fixing a relationship or ending it. This time, with C, I did not want to avoid that work. But I was scared of myself. I had no illusions about my own innocence. Whenever I heard myself saying, I’d never do that, I heard a false promise. We can’t imagine ourselves doing many things until we do them.

Four years in, it hurt to hold the things I loved about C alongside everything that had soured between us. But these things stubbornly remained: His wit. His loyalty. His belly laugh. His razor vision. One of my favorite things about being married to C was the company of his gaze. The things he noticed. His deep love for the ridiculous humans of this world. That’s why I wanted to text him about the selfie takers, and the couple on their awkward date. Some part of me loved his rough exterior—his many tats, his gruff candor, his quick temper—because it made his interior seem like a gentleness meant only for me. Me and shih tzus. Me and the characters in his novels. Even when things between us were falling apart, I always craved that feeling of wandering through the world with him—hearing what he noticed, seeing what he saw.

By the time our daughter arrived, we’d already been in couples therapy for three years, all but the first year of our relationship. Once a week, we went to a basement office and sat together on a loveseat that never felt large enough. The harder our home life got, the more guilty I felt for wanting to leave it. This was the same deluded faith in difficulty that made me starve myself at eighteen, running seven miles on the treadmill after six saltines for dinner. This same voice rose up again to say, The harder it feels, the more necessary it must be.

In my early twenties, the first time I moved to the city, I worked as a temp in a Midtown office building, passing my days in a grim cubicle, on a floor without windows, running database searches on high-asset clients to make sure they didn’t have criminal records. At the holiday party I got sloppy drunk on cheap wine and asked everyone if the rumor was true, that we didn’t have any windows because a temp in Miami had jumped from one. Sometimes on my lunch breaks, I’d go to MoMA, just for twenty minutes, just to stand in front of a Seurat painting of the ocean and the sky at twilight. It helped me remember the size of the world—his horizon full of shimmering dust, those tiny points of paint. Those twenty minutes of beauty felt more important than all the hours around them, but they also made me crave a life whose ordinary hours I wasn’t running away from. That life wasn’t something I felt entitled to. It was just something I wanted.

If writing was my great love—and I was starting to believe it was, perhaps more than any man would ever be—I often wondered if it was ultimately a form of self-love, a kind of poison. Maybe submitting myself to another’s needs—becoming a wife, and then a mother—was precisely the antivenom I needed.

In class, I spoke to my students about breaking open the anecdotal stories we all tell ourselves and others about our own lives. You have to dislodge the cocktail-party version of the story, I said, in order to get at the more complicated version lurking beneath the anecdote: the anger under the nostalgia, the fear under the ambition. I didn’t want their breakups summarized, I wanted specifics—wanted them stress-eating cookies as big as their palms, their fingers smelling like iron after leaning against an ex’s rusty fire escape.

Looking at those lovers, gleaming and entangled, I remembered the first time C and I went to dinner, at an Italian restaurant tucked inside a brownstone. As C walked me to the subway afterwards, it started raining. Dark spots speckled the sidewalk.

C offered me his jacket. I refused, saying it was my own fault I’d forgotten to bring a coat. He shook his head, amused. “So you deserve to be cold? Ridiculous.”

He draped his coat over my shoulders. “Just take it.”

He knew the universe didn’t give people what they deserved, anyway. You might as well stay dry while you could.

During a conversation two years earlier, when I was already unhappy enough to consider leaving, I told Harriet I was worried about the harm I would cause if I left. She told me I was right to worry. I would cause harm. She also told me no one moves through this world without causing harm. I’d wanted her to say, Don’t be crazy! You won’t cause any harm! Or at least, You’re in so much pain, you deserve to cause harm!

But she hadn’t said either of these things. What she said instead was neither condemnation nor absolution. It was just this: You have to claim responsibility for the harm you cause. You have to believe it’s necessary.