Months before my last beach holiday, I ripped out a page from a Victoria's Secret catalog and thought: Look like her by the time this bikini arrives. I then tacked the image to my bedroom wall (yep, like a frat boy) and used it as a benchmark of how hot my bod would be if I'd just drop a few pounds. But by the time the paisley spandex number arrived weeks later, I had lost 4 pounds — and gained back 3.

I'm a roller-coaster dieter — up a few pounds, then down, then right back up again. (More a jeans-are-snug mini coaster than a buy-the-next-size-up variety, but nonetheless ...) Since college, in attempts at scoring my ideal body, I've been my own personal Jenny Craig — never following a by-the-book regimen but always on some sort of low-carb or no-carb combination that I can never quite stick to. After New Year's, I coupled strength-training routines with a strict no-white-bread rule and soon dropped 6 pounds. But then I rewarded myself — skipping morning pilates classes and shamelessly hitting the Wendy's drive-through — and the scale shot back up another 4 pounds. Then a few months ago, when it came time to tie on my new string bikini for a Jamaican getaway, I opted for a no-breakfast-before-beach plan, which kept my stomach reasonably bloat-free. Of course, the minute any food touched my lips, my belly regained its undeniable jiggle.

No matter what the scale says, I'm convinced that my body is always 5 pounds off target. As Susan Roberts, Ph.D., author of The Instinct Diet and a nutrition and psychiatry professor at Tufts University, puts it: "It's never really about the last 5 pounds. People set weight-loss goals, and when they reach them, they'll set even lower ones. The early results act as positive reinforcement to keep going." Roberts gives an academic nod to what I've suspected all along: It's all about the chase. And in my case, if I ever actually maintained my goal weight, I'd have nothing to work toward, no reason to go to the gym.

True, exercising simply for the cardiovascular benefits would be the healthy thing to do, but I'm less motivated when the objective isn't as well-defined or tangible. As much as my Millennial generation is maligned for its entitled, coddled attitude, one thing's for sure: We're goal-oriented (even if we do expect excessive fanfare for our successes). So keeping myself chained to an always-distant weight-loss goal is just a reminder that I've still got work to do.

What's more, talking weight with my girlfriends and female colleagues is like men rattling off golf handicaps — it's a social lubricant. Diet denial would be like bragging that my body is perfect, which would earn me a one-way ticket out of the girls-only gabfest. As we go pound-for-pound, the envy over who's making more money or getting engaged is pushed out by the shared commiseration over our collective weight gain — it's a twisted form of group therapy.

I'll always bemoan the fact that I can't stick to my ideal weight and blame the self-sabotage on my perfectly healthy BMI and a knack for sucking in my gut. "If you're already a small size, it's very difficult to lose and keep off those last 5 pounds because your body is comfortable — you still fit into your clothes, so you don't feel the urgency to do it," says Lacey Stone, a personal trainer at Equinox Fitness Clubs in New York City. That's exactly why I slack off. But those 5 pounds still serve as my motivation to haul ass back to the gym or pass on double-dipping in the chocolate drawer at work. And I find ironic satisfaction in knowing that I'll never be satisfied.

What Do You Think?