For a long time it puzzled me how something so expensive, so leading edge, could be so useless. And then it occurred to me that a computer is a stupid machine with the ability to do incredibly smart things, while computer programmers are smart people with the ability to do incredibly stupid things. They are, in short, a perfect match.

Our instinct may be to see the impossibility of tracking everything down as frustrating, dispiriting, perhaps even appalling, but it can just as well be viewed as almost unbearably exciting. We live on a planet that has a more or less infinite capacity to surprise. What reasoning person could possibly want it any other way?

Science has been quite embattled. It's the most important thing there is. An arts graduate is not going to fix global warming. They may do other valuable things, but they are not going to fix the planet or cure cancer or get rid of malaria.

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.

"Croissant": However you choose to pronounce it at home, it is perhaps worth nothing that outside the United States, the closer you can come to saying "kwass-ohn," the sooner you can expect to be presented with one.

Hardly anyone ever leaves. This is because Des Moines is the most powerful hypnotic known to man. Outside town there is a big sign that says, WELCOME TO DES MOINES. THIS IS WHAT DEATH IS LIKE. There isn't really. I just made that up. But the place does get a grip on you.

Most of what has lived on Earth has left behind no record at all.