It was only two blocks, but the walk to our first day of school seemed to take forever. Mark, my son, the kid with the spectacles and shaggy brown hair, simply wasn't in any hurry to get there. He kept hanging back, counting butterflies, and telling me how everyone else in our neighborhood had a newer car than his dad.

It wasn't that he was unaware of the gravity of the occasion. He'd talked about it all summer. Each day, he'd wake up and ask, "Is this a school day, or a cartoon day." Cartoon day is Saturday, and its the only day of the week that really matters to Mark, and every other kid on our block.

He knew he had reached the age of ultimate maturity - and according to the custom of the land, it was time to get an education. But the scowl on his face warned, "It really isn't that big a deal."

Actually, Mark is no stranger to formal learning. He's been going to nursery school, preschool and kindergarten classes of one sort of another almost every day since he was 2 1/2 years old. And one day a couple of years ago when his parents took the wrong turn off the New Jersey Turnpike and passed by Princeton University, he announced. "This is my school."

Princeton doesn't take 6 year olds. At least none of the 6-year-olds in our neighborhood goes there. For them, education happens in a low, red brick building with white pillars in front at 600 Russell Rd. in Alexandria. It's called Maury School, and it looks like the kind of All-American place where Fred McMurray might send his kid.

By the time we arrived at 8:30 a.m. yesterday, Room No. 1 was full of anxious-faced children, girls with pretty new dresses, boys with bright colored new tennis shoes, the symbol of their manhood.

A kid with blond hair took one look at Mark, and declared, "You got glasses." Mark, my youngest flinched. This was the first day he'd worn the glasses in public. "They're for reading," he announced.

A few parents lingered for a moment, realizing that for much of the next five months the 20 children in the class would live in a world inaccessible to them. They would have their own secrets, their own hopes and traumas.

Clair Winslow, who has been teaching at Maury since 1952, the same year Mark's mother finished first grade, began the day slowly. She, passed out crayons, name tags and pencils. She asked Kimberly Johnson "are you kin to Billy Johnson?" She said "No." It was the first time in years, Mrs. Winslow said that none of her new students were related to any of her former students.

The room was a bright, airy yellow with colorful charts and pictures. A clown on a poster at the front of the room said, "Let's have a good day."

"Aren't you glad to be in school?" asked Mrs. Winslow, a handsome, slender woman with a firm manner.

"No," said the first voice to pipe up at the front of the room. It was soon drowned out with yeses, however.

"All's I want to know is where is the bathroom," a primly dressed little girl asked a little later. The bathroom turned out to be behind a door in the corner of the room. Mrs. Winslow said anyone could use it withour permission as long as it was unoccupied. During the next two hours, a little boy in a blue shirt used it three times.

The high point of the monring was when all the children gathered on the floor around Mrs. Winslow's rocking chair to tell her about what they had done during the summer.

Most everybody had spent the summer swimming, or going to the beach, although the one boy said, "I didn't do nothin." A pretty girl named Tosca was the most impressive. "I went to Hershey Park and King's Dominion both," she said. Everyone oohed and aahed. But my favorite was Karen. "I went to Washington, D.C., and bought a dog. It's nice," she said.

Later, there was paper work. Mark did nothing particular to distinguish himself. It's not that he lacks learning, I thought to myself. After all, he's watched Sesame Street since he was 1, and spends hours looking at books with titles like "Great American Battles," the "Starflight Technical Manual," and "Naval Aircraft, from 1939 to 1945."

He's a child of the mobile society. In six years, he's lived in five houses. He has trouble remembering the names of his grandparents, and to him "Roots" was something on TV last year. But he's street smart. He knows the really important things in life, like where they make the best pizza in town, when the "Muppets" come on TV, how to jump off a diving board, and how to handle himself in a fight with his older brother and hero, Chad.

In the cafeteria at lunch, his teacher said children have changed during her 25 years at Maury: They are smarter, more aggressive, they know about rockets and ships. They have traveled more . . . And more of them are lefthanded.

Mark is lefthanded. When I left him at noon, he had taken his glasses off and hidden them in his desk. He grabbed my hand tightly, as I said goodbye. He looked alone, and a little scared.

His mother picked him up at the end of the day. How was school? she asked. "Fine. They kept me busy all day," he said. "And we had a hamburger for lunch."