And then suddenly I would realize that I couldn’t remember, hadn’t actually consciously experienced, any of the last forty-seven properties I had vis… - Bill Bryson

I knew more things in the first ten years of my life than I believe I have known at any time since. I knew everything there was to know about our house for a start. I knew what was written on the undersides of tables and what the view was like from the tops of bookcases and wardrobes. I knew what was to be found at the back of every closet, which beds had the most dust balls beneath them, which ceilings the most interesting stains, where exactly the patterns in wallpaper repeated. I knew how to cross every room in the house without touching the floor, where my father kept his spare change and how much you could safely take without his noticing (one-seventh of the quarters, one-fifth of the nickels and dimes, as many of the pennies as you could carry). I knew how to relax in an armchair in more than one hundred positions and on the floor in approximately seventy- five more. I knew what the world looked like when viewed through a Jell-O lens. I knew how things tasted—damp washcloths, pencil ferrules, coins and buttons, almost anything made of plastic that was smaller than, say, a clock radio, mucus of every variety of course—in a way that I have more or less forgotten now. I knew and could take you at once to any illustration of naked women anywhere in our house, from a Rubens painting of fleshy chubbos in Masterpieces of World Painting to a cartoon by Peter Arno in the latest issue of The New Yorker to my father’s small private library of girlie magazines in a secret place known only to him, me, and 111 of my closest friends in his bedroom.

The makers of sneakers also thoughtfully pocked the soles with numberless crevices, craters, chevrons, mazes, crop circles, and other rubbery hieroglyphs, so that when you stepped in a moist pile of dog shit, as you most assuredly did within three bounds of leaving the house, they provided additional absorbing hours of pastime while you cleaned them out with a stick, gagging quietly but oddly content.

The Smokies seem to be in the process of losing most of their mussels. The National Park Service actually has something of a tradition of making things extinct. Bryce Canyon National Park is perhaps the most interesting—certainly the most striking—example. It was founded in 1923 and in less than half a century under the Park Service’s stewardship lost seven species of mammal—the white-tailed jackrabbit, prairie dog, pronghorn antelope, flying squirrel, beaver, red fox, and spotted skunk. Quite an achievement when you consider that these animals had survived in Bryce Canyon for tens of millions of years before the Park Service took an interest in them. Altogether, forty-two species of mammal have disappeared from America’s national parks this century.