When it comes to this subject, I consider myself an expert. In 1998, I was awarded first place in the prestigious Worst Boyfriend in All the World, Possibly Even All of History and Maybe Other Planets, Too competition. I could give you all of the details about him, but it’s probably better for the sake of this discussion for you to just imagine the worst person in the world for someone you care about to date: your friend’s a vegan and she’s dating a hunter, or your friend is a snowman and he’s dating a grill chef, or your friend is a Lorax and he’s dating a Once-ler. That’s how the people close to me felt about this guy. Actually, I’m worried that you haven’t imagined someone bad enough. Can you go back to your person and make them just a bit worse? It wasn’t just a matter of people not being able to stand “Joe” personally, they also very much wanted me to break up with him.

At the time we were, uh, courting, one of my friends was also seeing a no-goodnik. We had an understanding that we could talk to each other about our relationship woes because the other one wasn’t going to say, “Get rid of him!” We empathized or chuckled knowingly. “He took all the money out of my wallet,” one of us would say. “I know, same thing happened to me!” the other would reply. Unlike in our conversations with our other friends, there was no threat of lecture.

People often ask, “What were you thinking?” I can say that that woman who married one of the Menendez brothers, Safia Gaddafi, and I were all presumably thinking something along the lines of “I can’t wait for my mother to meet him!” And “Sure, I know he murdered his business associate/ parents/ millions of innocents, but people can change!”

Both of my brothers are married to wonderful, lovely, smart, charming women, and these unions were very welcome in our family, because many of their ex-girlfriends had made my mother and the rest of us continuously smack our foreheads. Now, mind you, neither one dated any ex-convicts, but in my family not having a good sense of humor is a form of crime, so they were in fact current convicts. At least the bum I dated was funny.

When I was working at Häagen-Dazs in college, I became friends with someone I never would have known otherwise. Angelica was a former cocktail waitress and the most down-to-earth person I had ever met. There wasn’t a shred of pretense to her. She had this boyfriend, a guy I’ll call Al, because he looked exactly like a white Al Sharpton. She brought him to my apartment for dinner parties on a couple of occasions. He did things like feel the bread I put out to see if it was warm, and then tsk disappointedly when it wasn’t. And then, though he was the only one who really didn’t belong there, he chose to commandeer all of the table conversation, regaling us with his inimitable yarns. I think it’s important here to share his top three yarns:

Yarn Number One: He worked as a custodian in a senior center where there was an elderly lady who thought his name was Ted. So day after day she’d say, “Good morning, Ted.” And one day he finally said to her, “FUCK YOU, MY NAME IS AL!”

Yarn Number Two: Al had to go to the DMV and renew his Class 2 Commercial Driver’s License so he could leave the door open to returning to truck driving if his hemorrhoids ever went away. So he was on line at the DMV and the woman working there, who according to Al wasn’t even a native English speaker, had the nerve to ask him for his green card. Could you imagine that someone didn’t recognize that he, Al, was a red-blooded, hemorrhoidal American? So he said to her, “I don’t got no green card, but how ’bout I show you my DICK?”

Yarn Number Three: Jehovah’s Witnesses came to his door and asked if he wanted to hear some scripture, and he said to them, pointing, “Read my shirt.” Which said: GO FUCK YOURSELF!

The thing about Al, though, was not just that he was an obnoxious racist breaker of some poor father’s heart, but that he was also married and had kids. I think his wife had some awful disease, too. Somehow, Angelica didn’t see him as I did, and unfortunately in that case, I had to stop being friends with her outside of the ice cream parlor.

My own roundly disliked boyfriend Joe was damaged goods. He was my first rescue dog, except he was a dog who had committed armed bank robbery. I thought that his troubled background and the fact that he’d never been in therapy or had anyone give him a break was the cause of his problems. I would introduce him to analytical thought and kindness. His father died when he was a kid, and he suffered as a result. “Lots of people suffer! They don’t rob banks!” my father pointed out.

When I think back on that period, my nervous leg starts to shake. I feel a combination of anger and remorse, but I also remember the thrill of being with him.

* * *

But there’s doing something you know is dangerous for the thrill of it, and then there’s being blithely convinced that something that is clearly problematic to everyone else is just fine. Somewhere between the age of three and four, I was playing horsie in the freshly snow-covered backyard of my best friend Rebecca’s house. The game was pretty simple: I tied a winter scarf tightly around her neck and she ran around the yard as I pulled it yelling, “GO, HORSIE!” At some point her mother came screaming out the door and told us to stop and — screaming, screaming — “NEVER PUT ANYTHING AROUND ANYONE’S NECK!” I listened as we took the scarf off, but honestly I thought she’d gone completely mad. I had no idea that what we were doing was dangerous, and even after she said it, I still thought she’d gone off the deep end. It was a little blue hand-knit woolen scarf with small white snowmen scattered around it. It wasn’t a knife or fire or a gun. In the years since, that moment has come back to me again and again — even in college I still thought she had overreacted. It didn’t really click until I had a kid of my own who did stupid things and scared the crap out of me. But it was the not getting it at the time and thinking that I really knew better that is poignant for me.

I’m now friends with a lot of my daughter’s school friends’ parents. There was one woman I really liked, and Violet liked her son. I could totally have seen us getting together socially as families, but her husband made my head explode.

He was one of those people who think they know everything and no one else does, not to mention he studied art and film and music in different grad programs, so he was a cultural snob. He would always be gifting me with his opinion, which I didn’t want, or telling me about a composer or artist only he knew about, and why I couldn’t possibly even conceive of the relevance and import of this person because I, like everyone who isn’t him, am too stupid to be alive. One time we were hanging out with the kids at a school picnic, and I made the mistake of saying I never get to movies anymore, and he started telling me the plot of an artsy-fartsy foreign film that I had to see. I was to hire a babysitter and see this film because it was simply the most important cultural event of our time!

“Is Jennifer Aniston in it?” I asked. “’Cause I don’t see any movies without JenAn.” I added, “I just love her hair.”

He sputtered at me and started talking about someone named “Mee-nu.” The fact is, I was a cinema studies major at NYU. I know a thing or two about movies, but I wasn’t going to get into it with him; he had so much invested in being the most knowledgeable.

I couldn’t for the life of me figure out why this sweet woman put up with this pompous ass. There was no pretention about her, and that was all he was. She was in his thrall, and I wanted to throttle him. I was secretly relieved when they moved to London, because although I’d miss her and their kid, I knew those Brits would wipe the intellectual floor with him.

* * *

My Aunt Mattie and I used to watch a considerable amount of daytime TV shows featuring women or men suing a former boyfriend or girlfriend for taking them for a ton of dough. Or women who repeatedly have a need for the televised revelation of the results of paternity tests. There is a woman who was on “Maury” 19 times — NINETEEN TIMES — with 19 different men, checking to see if any of them was the father of her kid. Think about that. You’re basically looking back on, at most, an eight-week period of time. That means you’ve slept with at least 19 men in that span of time; clearly for this woman it was more because none of them was the match. And there you are with your little 18-month-old baby with the elastic bow on her head, waiting to see if maybe this time you guessed right. My favorite part is the expression on the woman’s face when the guy gets up and fist pumps because he’s not the father. She sort of looks up and around. “Gee, I thought it was him. Hmm, so who else, who . . . else . . . ?”

Now we’re talking about the minds of other people. You, gentle reader, are sane. But maybe at one point you did something that I would consider crazy. True, I dated a mobster, but I’d never jump out of a plane. Or ride in a hot air balloon. Or go on Space Mountain. Or get in a car with a person who has had too much to drink. There are lapses in judgment that can sometimes last a lot longer than we hope. And what was most important to me when I was going through it was for people to try to see what I saw, because then at least when they gave me advice, I listened. I didn’t take it, but I did hear it.

What you really want to do with your friends with unfortunate partners is try to remain a good friend to them. It’s a complicated and delicate situation; you don’t want anyone’s feelings to be hurt unnecessarily. It’s also important to look at your opinion of this person and make sure you’re clear about why you feel this way, and that it isn’t about you. Hopefully, whatever you’re seeing in this unsuitable suitor will eventually come to light for your friend, too. Those things do have a way of working out like that. And then you can be there and hold your friend’s hand and tell them, “You know, I never liked him.”

Reprinted by arrangement with Riverhead, a member of Penguin Group (USA) Inc., from “FRIENDKEEPING: A Field Guide to the People You Love, Hate and Can’t Live Without” by Julie Klam. Copyright © 2012 by Julie Klam