I had conversations with Ben a few years ago about his economics research (incidentally related to some research I was doing at the time). I wouldn't have guess

I had conversations with Ben a few years ago about his economics research (incidentally related to some research I was doing at the time). I wouldn't have guessed he was close to 70. He's a sharp guy. (I also think his economics research is excellent, and the comments elsewhere about his track record aren't particularly fair.)