Sometime in the mid-1990s my mother uncovered some photos of me as a child that I'd never seen before. I flipped through them and found one that fascinated me. It showed me at about nine months or so, crawling on the grass in Golden Gate Park. My tongue was sticking out of a corner of my mouth, and my chubby little face was beaming. I looked like I was having a great time.

I finally figured out, after a few days, what was so compelling about the picture. I had never seen a picture of...

