We're driving to yoga class in my 1999 Honda Civic, the car I bought brand new the year I turned 24, moved across country, took a full-time career-oriented job and started mourning the imminent death of my lingering teenage self.

Back home four years later, my mom and I are attending weekly yoga classes in which my older sister oversees the back bends and warrior poses of a half dozen overweight middle-aged women.

It's exactly the type of suburban nightmare that would have launched me into a cold sweat as I committed to a new job and my first car payment and struggled to come to terms with the inevitability that my life would soon better fit the script of Thirty Something than Rock 'N' Roll High School.

The 16-year-old me felt so firm in her convictions to never toe the corporate line, never amass the trappings of the middle class, never settle into the dim oblivion of the American dream. And as the trappings started to accumulate and the bills started rolling in, I agonized that that rebellious inner child would soon be crushed under the weight of responsible adult paperwork.

The voice from the cramped back seat of my fuel-efficient car is a lifeline to that spiky-haired, self-righteous kid.

Jil, a new friend of sister's, is coming to yoga, along with her preteen daughter. In a few intense months, the mother of two, who runs a magazine with the heart-breakingly earnest title of Enlightened Woman, has developed a nearly Single White Female enthusiasm for my sister Shelly.

"I've been waiting on pins and needles, but Shelly finally did it," she squeals in a giddy voice every bit as junior high as her daughter's. "She called me her best friend! I didn't think she'd ever say it!"

Suddenly I understand why the suffocating nostalgia/dread of my quarter-life crisis subsided after I crested 25 and headed ever closer to 30. Our younger selves are clearly a lot more tenacious than I gave them credit for.

I thought my post-college life would entail more drastic changes than a job I liked and a car whose oil I might check. It was as if Scripps Howard and American Honda Finance Corp. would send more than paychecks and bills every month: they would send me a new adult-model personality that wanted to organize a bake sale and keep a file of clipped coupons.

Gone were the days of making out with a stranger with whom I didn't share a language before passing out for the night on an Amsterdam bench. Any minute now, I would find myself dating a man who golfed and wore an ironed pocket T-shirt tucked into his khaki shorts.

But Jil's story, which goes on to compare my sister's friendly revelation with a boyfriend's tentative first "I love you," is the perfect antidote to my fears of a full-scale adult-mentality takeover.

I realize we're all just as childish, self-conscious and catty as ever, thank God.

A quick inventory of recent outings with my 30-something friends allows me the relief of adding recklessness, substance abuse and social awkwardness to the list of traits we've retained.

I think of Memorial Day weekend, when we drank several cases of beer and encouraged my friend Jason, a 36-year-old man who's unemployed and living with his parents, to jump his Toyota truck off a five-foot mound of dirt outside a friend's house. All four tires lifted off the ground for a few glorious seconds before coming back to Earth with a tremendous force that slammed the window on his cab-shell open and shut and drove the trailer hitch several inches into the ground. Jason emerged from his truck, checking his tires and windows before deciding that the mark made by the trailer hitch would be a good gauge to see if any other cars could beat his distance.

I think of my friend Chris, who after a 10-year career as a CPA, recently returned to school to become a veterinarian. The majority of a recent book club meeting was spent with him agonizingly recounting standing up to a freeloader who tried to take answers from Chris and his lab partners. With great distress, my friend finally summoned the courage to pointedly insist: "You're not in our lab group!" The recollection makes Chris wring his hands.

I think of my friend Dave, who invited me to a concert earlier this month, during which he actually inhaled a joint because he was trying to get it burning red hot before passing it to our neighbor. When the show ended, we spent two hours hiking through the dark, shrubby trails behind Red Rocks because we couldn't find our cars.

Yes, we're older. Many of my friends are married with kids, and I'm looking to buy my first house. But it's now clear to me that the shifts are more subtle and far less threatening than I suspected as a new adult suspicious of the demographic she was joining.

I do have a reliable car, a dozen monthly bills and concerns over mortgage rates rising before I find the right house. I don't go out as often as I used to, and I tend to be a bit more picky about my sleeping arrangements when I travel. But none of these things have robbed me of the combination of silliness and skepticism that I like to think defined my formative years.

I do have a 36-year-old boyfriend, Pete, and he has one pair of khaki pants. But they're soaking in the sink because he puked on them after drinking too much during our $150 anniversary dinner.

Gagging on the smell of regurgitated red wine, mussels and mascarpone that fills our apartment, I start looking for my wallet. With mounting dread, I look toward the bile-laced water and try to stifle the flickering recollection that Pete had it in his back pocket.

Before heading to work, I pick the pieces of my adult identity out of the sink and lay them out to dry in a sunny spot. Two credit cards. Debit card. Driver's license. Health insurance card. King Soopers card. Dental appointment reminder. Realtor's business card.

I'd rather not have this mess to deal with. But inside, a teenage goth girl, a coffee house philosopher, a ditcher of classes and champion of Pac Man, is celebrating her victory.

This sucks, I realize, but it beats the hell out of clipping coupons.

Amy Hebert is a Colorado native who continues to make her home in the Mile-High Queen City of the Plains. She writes for a Boulder newspaper and reviews books for Enlightened Woman magazine. For fun, she street-hikes, drinks girl-drinks and gets bit by her cat.

In 10 years, she will be overdue for a tetanus shot.