I’m waiting for a friend at a wine bar and I see that the guy a couple of stools down from me keeps ostentatiously checking the late-model smartphone that lies before him on the granite countertop. He has the all-black Samsung BlackJack, which happens to be the coolest-looking smartphone there is—at least until the iPhone comes out—and he’s wearing jeans that look like they cost $400, and his haircut was probably half that. I also notice that he’s got an expensive- looking European leather briefcase at his feet that he no doubt calls an attaché.

I’m thinking, what a douchebag.

And then I think, wait a second. I’m here, at this wine bar, just as he is. And frankly, when the iPhone does come out, I intend to get it (even though it’s slated to cost more than $500) to replace the Treo I’m currently carrying. (Also: I really should check my e-mail right now.) And I’m due for a (quasi-expensive) haircut, in fact. And where’s the freaking bartender already? And . . . and . . . and . . . am I a douchebag? I have met the enemy, and he is . . . me?

There’s a fine line—a harrowingly fine one—between being the guy who sneeringly points out That Guy in public and actually being That Guy yourself. I am not, of course, suggesting that I’m anywhere near being a douchebag on the order of, say, bad-boy heir Brandon “Firecrotch” Davis. But a run-of-the-mill, everyday douchebag? Maybe sometimes. Possibly semi-often. The point is, the burgeoning class of people constantly calling other people douchebags are almost certainly members of the doucheoisie themselves. It’s the perfect insult for our times, because the insulter can congratulate himself for being provocative, slightly outré, a little extra nasty. But when it comes to wielding a word that originated on the playground, playground logic reigns: It takes one to know one.

The surprising thing about douchebag, which has become the current default term of disparagement—deployed with relish by everyone from Jon Stewart to every other blogger—is that most likely your grandfather used it too. “It was very popular among my generation in my teens and twenties,” says Dennis Preston, a professor of English at Michigan State University who is an expert on American slang. Preston is, by his own description, “pushing 70.”

Over time, the word has come to denote “somebody who can’t help but to be an asshole,” says Grant Barrett, a co-host of the radio show “A Way With Words” at KPBS in San Diego and the editor of the Double-Tongued Dictionary website (doubletongued.org). “Somebody who’s blithely in your way, in your face, or in your parking space.” Only thing is, if someone’s in your way, you’re probably in his way. If a douchebag is getting—demanding—something and that’s bothering you, it’s probably bothering you because you think you are entitled to it.