The answer is that the success of any kind of social epidemic is heavily dependent on the involvement of people with a particular and rare set of social gifts.

There's no idea that can't be explained to a thoughtful 14-year-old. If the thoughtful 14-year-old doesn't get it, it is your fault, not the 14-year-old's.

David Epstein, the author of the best book on athletics in recent memory - "The Sports Gene" - wrote to me to say that he thinks I'm being overly generous. He points out that, for years, there used to be an "all-star challenge" on television, in which the best professional athletes from a variety of sports competed in a kind of makeshift decathlon.

Courage is what you earn when you've been through the tough times and you discover they aren't so tough after all.

My earliest memories of my father are of seeing him work at his desk and realizing that he was happy. I did not know it then, but that was one of the most precious gifts a father can give his child.

It changes how people read you if you believe in God. It gives insight into your motivation, how you look at problems and how you deal with people.

What a gifted child is, in many ways, is a gifted learner. And what a gifted adult is, is a gifted doer. And those are quite separate domains of achievement.