Few of us think to judge whether we’re having a " happy childhood " until much later, when we find that we’ve suddenly, inexplicably, become what we never quite believed we would ever be: adults. Often this realization, usually accompanied by an audible thud, leads us to consider, with astonishing voracity and attention to detail, every childhood event that may have brought us to this curious state — even if, as in my case, you realize that your childhood was, for all intents and purposes, a happy one.

I was moved to take such an inventory recently when I found myself lying on the floor of my own kitchen, in my own apartment, which was, at the time, filled with friends who had come for a potluck dinner. I wasn’t sick, or drunk, or having a " moment " ; I was just tired. Actually, " exhausted " is probably a more apt term, given that I was lying on the floor in the middle of a party. But when asked by my friends, " What the hell are you doing lying on the floor? " , I didn’t know quite how to answer. It had been weeks since I’d slept more than four or five hours a night, and as far as my fatigued brain could recall, there was no good reason for it: I wasn’t working particularly hard, or playing particularly hard. I had no new love interest. It was depressing, thinking about all the things that should have been keeping me up at night, but weren’t.

It is at moments like these — desperate, lying-on-the-floor moments — that taking stock of one’s childhood is useful. It is amazing how, when plugged into the right scenario, events you haven’t considered in a decade or two can suddenly seem to explain lifelong trends. And for me, staring up at the rear ends of the people I hold most dear, the answer to the big question, " How did I get here? " — a literal question no less crucial to the moment than its figurative, more existential counterpart — became clear: the Muppets. Yes, without those lovable, laughable, forever-head-bobbing characters and my five-year-old self’s intense desire to stay up that extra hour past bedtime to watch them, I would’ve been a normal potluck-dinner host, making sure all my guests had their fill of beer and spinach dip.

It is only in a " happy childhood " that the most dreaded words are " time for bed. " To my Muppet-crazed mind, there was no worse declaration. Especially because when eight o’clock rolled around and I heard, on my way up the stairs to my room, the first notes of The Muppet Show’s joyous theme song, my older sister would be looking forward to enjoying the Swedish Chef, and, I imagined, laughing mercilessly at my misfortune at having been born too late for Muppet-watching.

To miss things is the fate of the youngest child. When you go to bed, exciting things happen. So exciting, in fact, that you can’t even imagine what they might be. But you know they are good. Muppet-good.

I still don’t know exactly what I missed during those years of trudging up the stairs to bed while everyone else — the whole world, it seemed — got to stay up. And so I seem to be spending the late nights of my adulthood in search of that lost time, in search of the good stuff. Most nights it’s not clear exactly what that good stuff is; often I don’t find anything more exciting than a drink with friends or a late-night movie. Sometimes I think what I’m seeking is only the pleasure of knowing that I can stay up as late as I want, to inhabit the world when everyone else has gone to bed. To be the last one up the stairs.

Problem is, in the morning there is work to attend to, laundry to do, errands to run. The kinds of things that make up the audible thud of adulthood. Not impossible to accomplish, but significantly more challenging when exhaustion has made the kitchen floor seem an appealing place to take a little rest. Which is why every Sunday night, along with other weekly promises for self-betterment, I vow to get more sleep. Somehow, though, these promises never seem to stick.

I’m not the only one who — knowing that with a little more sleep I’d probably live longer, be nicer to telemarketers, and brake for pedestrians — can’t seem to pull it off. Friends who spent their childhoods wishing they could stay up with the Big Kids are now funding the publishers of those More Sleep, Happy Life self-help books and the manufacturers of Tylenol PM. Recently, a friend of mine, one of those youngest children who apparently takes bad manners and the threat of early expiration very seriously, acquired a lifetime supply of earplugs and a special mask that makes him look like Jeff Goldblum in the early stages of The Fly. But besides causing him to look like an insect, his desire for a good night’s sleep only seemed to make him nervous about not getting what he was after. And as most of us have found at one time or another, worrying about falling asleep is a sure-fire way to stay awake.

We youngest children know we should sleep more, and it’s not for lack of trying that we don’t. But I wonder if those years of fantasizing about after-bedtime life has made an irreparable imprint on our psyches. So while lying on the kitchen floor was not my best moment, in a certain way, it worked for me. I still don’t want to miss out. And though I’ve never seen the Muppets on late-night TV, I have my suspicions that someone in programming is just waiting for the night I decide to throw it in early.

Rebecca Wieder, who wrote this column at 3 a.m., can be reached at rebezca@juno.com