ecently, I started substitute teaching. I had some time on my hands and a few exorbitant speeding tickets to handle. So I xeroxed my certification, took a test - a TB test, that is -- and before I knew it, I was Miss Hepola again. "Miss H," if you prefer.

"Do we have a substitute today?" one kid always had to ask.

"I don't know," I said. "What do you think?"

I was filling in for a tidy and fantastically organized woman who had left what seemed to be an instructional novella on Post-It Notes around her desk. "The kids are to complete their world explorer map." Whatever that is. "If they finish their world explorer map, they are to start on next week's vocabulary." Which I'm sure will happen. "No children may go to the bathroom, to their lockers, or to the office." And another thing!: "They may not chew gum."

I didn't mind the strict rules - it's much easier that way. Besides, the kids were used to it. This is a rich and prestigious middle school, part of an elite school district recently selected by Newsweek as the 14th best in the country. (I am unaware of their criteria, but I believe it had something to do with the high ratio of assholes to Hummers.) This makes subbing a much easier, and in some ways more boring, affair. Infractions are the same in every class - playing with hand-held computers, working on other homework, chewing gum. No cussing. No attitude. Where were the dangerous minds, the blaring rap music, the hard street truths? Why didn't I think of recruiting them into a rock band?

"Do you know what Compton is?" one student asked another as they colored in their map. "It's the ghetto of Dallas."

The students hadn't changed much since I went to school here 15 years ago. Kids wore T-shirts trumpeting their family's last vacation - Park City, Maui, Estes Park. The dumbest ones wore the Ivy League sweatshirts. Most of them were sweet and polite, some rude and snotty, but the most interesting ones seemed to be ruffled in the corner with their shoes untied. There was this one kid. We'll call him Timmy.

"I don't know why we have to color this map," he said, scribbling with map pencil across South America. He had a wild patch of red hair and a shirt that read, Jim Morrison --American Poet. "Look at this, I'm 12 years old and I'm coloring. When am I going to use this?"

"Actually, Timmy, every good college requires a coloring test." This amused me at the time.

"You're kidding," he said, "but you're funny."

Later, as I patrolled the room, hoping to find illicit notes, Timmy walked alongside me. "So how is your day as a substitute going?" he asked, his arms clasped behind his back in imitation of me.

I shrugged. My feet hurt. I was kind of hoping we'd get to watch a movie.

"I think you're doing a fine job," he said. It wasn't mocking, it was more like false flattery.

"I was a teacher once. Long time ago."

"You're too young!" He clutched his chest. "I don't believe it."

I looked at him and rolled my eyes. He was chewing gum. He'd left his shoes underneath his desk. Why is it that kids who break the rules sometimes seem to be the only ones worth teaching?

Toward the end of class, the kids clamored and elbowed to be the first to leave. It was like a tiny, well-dressed rock concert. "Ow! My eye!" someone said as the throng undulated.

"Can we leave early?" they wheedled. "Just a minute? A second?"

For a seventh grader, time must come in such cruel proportions. Hours of class crawl by. Extra seconds during passing period are like gold.

When the bell finally rang, I opened the door and they galloped out like the start of the Kentucky Derby. "Get out of my classroom!" I teased them as they left.

"This isn't your classroom," one girl snipped over your shoulder.

For a second, I forgot.