Then I reached my twenties. And the early twenties did seem to last forever. When I heard acquaintances a few years older lament the end of their youth, I felt smug, not yet in the danger zone myself. I had plenty of time. Until about age twenty-seven, when the days of being carded were long gone and I began to marvel at the sudden acceleration of years (reminding myself of my mother's annual monologue as she pulled out our Christmas decorations) and the accompanying lines and stray gray hairs. At twenty-nine the real dread set in, and I realized that in a lot of ways I might as well be thirty. But not quite. Because I could still say that I was in my twenties. I still had something in common with college seniors.

I realize thirty is just a number, that you're only as old as you feel and all of that. I also realize that in the grand scheme of things, thirty is still young. But it's not that young. It is past the most ripe, prime child-bearing years, for example. It is too old to, say, start training for an Olympic medal. Even in the best die-of-old-age scenario, you are still about one-third of the way to the finish line. So I can't help feeling uneasy as I perch on an overstuffed maroon couch in a dark lounge on the Upper West Side at my surprise birthday party, organized by Darcy, who is still my best friend.

Tomorrow is the Sunday that I first contemplated as a fifth-grader playing with our phone book. After tonight my twenties will be over, a chapter closed forever. The feeling I have reminds me of New Year's Eve, when the countdown is coming and I'm not quite sure whether to grab my camera or just live in the moment. Usually I grab the camera and later regret it when the picture doesn't turn out. Then I feel enormously let down and think to myself that the night would have been more fun if it didn't mean quite so much, if I weren't forced to analyze where I've been and where I'm going.