I got my first nemesis in fourth grade. His name was Ofer. 

He was my nemesis for two reasons: 1) I was totally jealous of his name, which started with a vowel and was therefore cooler than "Matthew." 2) Even though he was short like me, he was amazing at sports.

This wasn't fair. And therefore he was dead to me.

My strong feelings about Ofer -- (in retrospect, not such a cool name, huh?) -- had nothing to do with his personality, because Ofer and I were in different classes and barely interacted at all.  

But he was still my nemesis. I looked down on him for no good reason other than the fact I looked up to him, which I also did for no good reason.

Since Ofer, I've had a succession of nemeses. And this, I'm convinced, is a man thing.

It's not that women don't hate each other. But men have a biological predisposition toward competitiveness, making us almost crave enemies.

A 1998 study at King's College Research Centre in Britain enlisted students to keep diaries of their competitive interactions and found that men compete with each other more than women compete with other women. Men are also more likely to use physical rather than verbal aggression.

Unfortunately, I'm not really built for a fight, and I've been pacified by an American culture that insists fists don't solve problems.

So even though I'm purely male in creating epic competitions against other men, I'm totally female in the way I deal with it: verbally, or not at all.

My nemeses typically fit the description of the kind of person the Greek goddess Nemesis was responsible for punishing: someone with excessive pride, undeserved happiness or good fortune.

In other words, my nemesis is someone who makes me acutely and uncomfortably aware of my own inadequacies and insecurities.

Men are inherently player haters, and if I think that another guy got some luck that was supposed to go to me, then I will hate him.

Right now, for example, there's a little man who lives in my neighborhood whom I've met three times. Each time, he has not remembered my name. Each time, I've praised him pathetically for the new book he wrote. Each time, I've gone to the bathroom afterward and cursed at the urinal for him being a published author without really paying his dues except for having the skeezy-intellectual personality loved by book publishers and other people who don't have real jobs and sleep 'til 11 and hang out in coffee shops looking for cocktail-party conversation pieces in The New Yorker.

This guy is a perfect nemesis for me because he has accomplished something I haven't. And that is unfair.

My nemesis in college was in a rival fraternity and lived next door to our fraternity house. We had regular Saturday night pushing and shoving sessions with these guys -- which is another study in ridiculous male competitiveness, by the way, and somewhat embarrassing to think about years later.

But during the week, the nemesis and I had English class together where we would stare each other down. We never spoke. We just stared. I hated him.

Three years later, I ran into him at a Phish concert. Perhaps it was the good vibes of the tunes or the mushrooms he was tripping on, but he gave me a bear hug. We had a good old time hanging out.

This, of course, proves that nemeses are silly personifications of excessive testosterone. And yet they're totally necessary for my well-being.

I need a foil in my life, someone I can focus my aggression toward. Recently, I've found a new nemesis: Glenn Sacks, a self-described "men's columnist" who, based on the TV appearances he brags about, is considerably more famous than I am.

Since I don't know of another "gender columnist" besides myself, this "men's columnist" will do. Sacks qualifies as having undeserved good fortune -- because he makes a living saying things that are entirely wrong!

Zinger! Looks like it's on, Mr. Sacks. I will harbor unwarranted hatred against you for the next few months, or few years. As a "men's" columnist, I'm sure you'll understand.

This column appeared in the Courier-Post and Gannett newspapers nationwide.

POSTSCRIPT: An old friend later forwarded me Ofer's MySpace page. It turns out that not only did Ofer do two tours in Iraq, but he was a MEDIC there, and on his profile he lists his mother as his hero. I really know how to pick 'em. As for Glen Sacks, I got three weeks worth of hate mail from his supporters.