Edvard Munch, Jealousy, 1907.

For what we suppose to be our love or our jealousy is never a single, continuous and indivisible passion. It is composed of an infinity of successive loves, of different jealousies, each of which is ephemeral, although by their uninterrupted multiplicity they give us the impression of continuity, the illusion of unity. —Swann’s Way

Regret is a waste of time. Everybody knows that. But there are still times when I regret the energy I wasted through many years of undermining my boyfriends’ exes.

I was young and jealous and insecure. Even at the time it felt bad. But in low moments, I would hear the poison oozing out of me, petty and pathetic and sad. “I’ve always thought people who said they preferred early Fleetwood Mac were trying a little hard,” I might remark, idly, while looking at records. Because six months ago he had mentioned in passing that his old girlfriend felt that way!

Or, “I mean, there was a time when I wanted to move there … but you kind of outgrow that, you know?”

Did I even believe these things? I think I came to believe them. And the poor guy would nod absently, or say, Yeah, or worse: “Huh. Sarah used to say that.” And I’d say, “Oh? Well, I didn’t mean her. Obviously.” And in the stupid way of young men, he’d let me insidiously build my case, and probably internalize some of it; and if anyone had asked, he would probably have said I wasn’t jealous, that I was cool with their still being friends, not threatened at all.

I wish, sometimes, that I could take that back. I wish there were a terrible, ironic e-card for it: “I’m sorry for the bitchy things I implied about your ex’s taste in films,” with a line drawing of a man riding a velocipede or something. I wish I could say, “That backhanded remark about boy-shorts came out of somewhere dark and ugly and it has nothing to do with her. Please erase all that. Don’t let it color your good times.” Is that my legacy, that ugly revisionist history? There are days it gives me comfort to think that maybe, somewhere, someone has done the same of me, or maybe found one of the satisfyingly unflattering pictures of me online, and that it has nothing to do with anything real.

And other times I think with wonder how much energy I put into tearing down someone who didn’t fully exist to me. Imagine what I could do with that energy now! And after all, she was probably perfectly nice. Or, worst of all, hardly worth the effort.

Sadie Stein is contributing editor of The Paris Review, and the Daily’s correspondent.