When I was teaching college, I had lost three students in two years. One went out with two friends, drinking, at night, on a boat, and all three drowned. I hadn't liked him much. Yet it was a loss. I kept wondering what I could have done differently, so that I might have liked him more. The second I barely knew, even though he sat in my class day after day, and never shared, never showed me part of himself. He drove his car into a bridge coming home from work. Alcohol was not involved. I kept wondering what I could have done differently, so that I would have known him better. The third - now this was a kid I knew well. He had been home schooled, super-intelligent, the oldest of a brood of likable, shy kids. I saw him grow over two years, in different classes. He really shined when he earned participation in a special program that sent a group to study at Cambridge. He blossomed. He became a leader. He had a great sense of humor, and a taste for the unusual. He studied fencing....