The 1982 World's Fair in Knoxville closes Oct. 31. But should you be seized by the last-minute desire to load up a bus full of kids headed for Tennessee, don't say you haven't been warned.

"Was it worth it?" my boss asked, skepticism showing. "Oh yes," I replied, "it was quite an adventure."

"So was World War II," he declared, smug in the knowledge that no one could enjoy chaperoning 86 adolescents on a four-day trip that included two nights on the bus.

His reaction was typical. Friends thought I'd finally been driven 'round the bend by working-mother's guilt to volunteer for such a task. "I couldn't," shuddered one, "stand the din."

The truth is I was so flattered to be asked by my 12-year-old son to be one of the four adults to accompany his junior high school glee club to the World's Fair that any inconvenience paled into insignificance. As any parent knows, 12 is around the time kids become such aggressive peer-groupers, they rarely want to be seen in public with you anymore.

But of course, just as I'd plunked down my $116.75 bus fare (chaperones pay full freight) and was savoring the unique togetherness the trip offered, my son Woody began distancing himself, setting some very specific boundaries that meant one thing. The less he saw of me on this little excursion, the better.

"Make sure you're not in my room," he scowled.

"Whose room will I be in?"

"I don't know -- but it better not be mine."

As we assembled outside Alice Deal Junior High School, the scene looked like a Spielberg movie -- a platoon of children with backpacks and duffle bags and telegenically expectant faces ready to scale the unknown. Some clung to stuffed animals, the remnants of their childhood. Others reveled in their emerging sexuality, chasing each other, bantering about "cushy tushies" and getting their "cool" act down pat.

What a wonderful anthropological laboratory, I thought. Margaret Mead couldn't have done better.

The reverie was interrupted when Jean Lauderdale, Alice Deal's music teacher, took to a bullhorn to explain bus etiquette with the ultimate threat that troublemakers would be forced to leave their friends and sit with her.

"If I can just get down the road apiece without catching a headache from the hollerin'," groaned one of the bus drivers, holding his head.

"Do you do a lot of this?" I asked.

"Yes," he declared, "and it's been driving me crazy."

Before the trip was over, the bus drivers were in revolt. Such things as the grinding refrain of "Don't You Want Me Baby" sung over and over and the rat-a-tat-tat of peanut M & M's spilling down the aisle were all too much for people who aren't necessarily pre-selected for their love of other people's children.

I had steeled myself for far worse, and compared to some memorable jaunts in the family car, I never feared for anyone's life. At 7 a.m. we pulled into a fast-food outlet in Ashville, N. C. "They're only quiet because they're hungry," muttered the bus driver. "When they get something in their stomachs, watch out."

With everyone agreeing that the sausage tasted "like cow gizzard," we headed for Cherokee, N.C., where we toured a reconstructed Indian village, whizzed through a museum and were soaked thoroughly in a sudden storm. Then it was on to Gatlinburg, a tourist mecca where commercialization has reached such heights that vendors advertise "antiques of tomorrow."

As we regrouped in a restaurant parking lot, one young optimist penned a letter home to a friend:

You haven't missed much, believe me. At 12:30, Mrs. Lauderdale went around turning off lights and radios and telling everybody to shut up. At Cherokee, inevitably it rained. By the way, we had a terrible breakfast. We just finished lunch -- 8 hours since breakfast! The motel is rumored to have HBO. I look terrible in my swimsuit.

The motel in Sweetwater, Tenn., did not have HBO. But it had beds and air-conditioning and by 10 that night, it looked like heaven. Jean Lauderdale imposed a 10:30 curfew to assure the kids would be well-rested for their singing performance the next morning at the University of Tennessee -- ostensibly the reason for the trip.

Dr. Peter Holbrook, a parent volunteer like myself, took up sentry duty outside the motel.

"It was like a spy movie," he said. "You feel like a hundred eyes are trained on you, but you can't see anything but an occasional rustling of the curtain."

The morning of the performance, Lauderdale was dressed in five minutes flat -- the picture of propriety. "Stand Up/Smile/Personality," she commanded, as she led her weary glee club through a rehearsal. "Remember, you're showing off!"

After a rendition of everything from "All My Troubles" to "Fame," the festival "adjudicator" elaborately thanked the group for coming. "Now that you've buttered us up, what's the bad news?" yelled one of the kids. "Yeah, let us in on it," seconded another as Mr. Adjudicator crept away, leaving the nitty-gritty to Lauderdale.

One criticism, "not enough involvement of face," particularly stung. She didn't conceal her disappointment, but she didn't dwell on it either. "A high two is not bad," she told them. "It's not one. You can do better. Now, back to reality. Let's go to the fair!"

There were whoops of joy. The rest of that day and all the next, the kids fanned out at the fair and weren't seen until they lined up for the body count at the bus. Some loved the freedom; others hated it. One seventh-grader came back raving about "the cute guys working there" but never made it to the China exhibit, one of the fair's premiere attractions.

It also poured -- one of those legendary rainstorms that turns Southern clay into mud and that gave the Univ. of Tenn. its nickname, Old Orange. "My legs are killing me," moaned one of our dampened charges. "Do you have any idea how uncomfortable it is to walk on wet shoes?"

Dr. Holbrook, the dye running on his navy rain hat, replied evenly, "I think we all do." (In real life, Holbrook heads the intensive care unit at Children's Hospital, making him over-qualified to deal with the minor illnesses we had--and we had them all.)

The return ride was eerily quiet as exhausted kids slept. We arrived back at the school a little after 8 a.m. -- 80 hours after we'd left. Waiting cars scooped up the zombies as they stumbled off the bus, with most, like my son, sleeping away the entire rest of the day.

And no wonder. Since the trip, there's been an underground of stories of what went on while we slept. The web of insurrection even involved the motel night clerk , a lad of no more than 18 himself who spied boys entering a girls' room and, after warning the curfew-breakers to "be cool," invited himself in.

As for me, I was in on enough to give the trip a one--"plenty of face" -- and everything else.