Every twenty minutes on the Appalachian Trail, Katz and I walked farther than the average American walks in a week. For 93 percent of all trips outside the home, for whatever distance or whatever purpose, Americans now get in a car. On average the total walking of an American these days - that's walking of all types: from car to office, from office to car, around the supermarket and shopping malls - adds up to 1.4 miles a week, barely 350 yards a day.

Protons give an atom its identity, electrons its personality.

Yes, U.S. travelers dress better. The British are always so conspicuous in hot climates. They don't seem to wear shorts. American men seem to be comfortable wearing hot-weather clothing.

The real problem you get with humour is that you only have so many kinds of jokes within you, and you mine that vein a lot. This isn't just common to me; it's anybody who's funny.

The taipan is the one to watch out for. It is the most poisonous snake on Earth, with a lunge so swift and a venom so potent that your last mortal utterance is likely to be: "I say, is that a sn--

And before long there will be no more milk in bottles delivered to the doorstep or sleepy rural pubs, and the countryside will be mostly shopping centers and theme parks. Forgive me. I don't mean to get upset. But you are taking my world away from me, piece by little piece, and sometimes it just pisses me off. Sorry.

But I got a great deal else from the experience. I learned to pitch a tent and sleep beneath the stars. For a brief, proud period I was slender and fit. I gained a profound respect for the wilderness and nature and the benign dark power of woods. I understand now, in a way I never did before, the colossal scale of the world. I found patience and fortitude that I didn't know I had. I discovered an America that millions of people scarcely know exists. I made a friend. I came home.