In the late 1950s, the Royal Canadian Air Force produced a booklet on isometrics, a form of exercise that enjoyed a short but devoted vogue with my father. The idea of isometrics was that you used any unyielding object, like a tree or a wall, and pressed against it with all your might from various positions to tone and strengthen different groups of muscles. Since everybody already has access to trees and walls, you didn't need to invest in a lot of costly equipment, which I expect was what attracted my dad.

What made it unfortunate in my father's case is that he would do his isometrics on airplanes. At some point in every flight, he would stroll back to the galley area or the space by the emergency exit and, taking up the posture of someone trying to budge a very heavy piece of machinery, he would begin to push with his back or shoulder against the outer wall of the plane, pausing occasionally to take deep breaths before returning with quiet grunts to the task.

Since it look uncannily, if unfathomably, as if he were trying to force a hole in the side of the plane, this naturally drew attention. Businessmen in nearby seats would stare over the tops of their glasses. A stewardess would pop her head out of the galley and likewise stare, but with a certain hard caution, as if remembering some aspect of her training that she had not previously been called upon to implement.

Seeing that he had observers, my father would straighten up and smile genially and begin to outline the engaging principles behind isometrics. Then he would give a demonstration to an audience that swiftly consisted of no one. He seemed curiously incapable of feeling embarrassment in such situations, but that was all right because I felt enough for both of us — indeed, enough for us and all the other passengers, the airline and its employees, and the whole of whatever state we were flying over.

So this is a book about not very much: about being small and getting larger slowly. One of the great myths of life is that childhood passes quickly. In fact, because time moves more slowly in Kid World — five times more slowly in a classroom on a hot afternoon, eight times more slowly on any car journey of more than five miles (rising to eighty-six times more slowly when driving across Nebraska or Pennsylvania lengthwise), and so slowly during the last week before birthdays, Christmases, and summer vacations as to be functionally immeasurable — it goes on for decades when measured in adult terms. It is adult life that is over in a twinkling.

I knew how to get between any two properties in the neighborhood, however tall the fence or impenetrable the hedge that separated them. I knew the cool feel of linoleum on bare skin and what everything smelled like at floor level. I knew pain the way you know it when it is fresh and interesting — the pain, for example, of a toasted marshmallow in your mouth when its interior is roughly the temperature and consistency of magma. I knew exactly how clouds drifted on a July afternoon, what rain tasted like, how ladybugs preened and caterpillars rippled, what it felt like to sit inside a bush. I knew how to appreciate a really good fart, whether mine or someone else's.