"I spent a lifetime trying to avoid my own mental biases. (A) I rub my nose in my own mistakes. (B) I try to keep it simple and fundamental as I can. And I like the engineering concept of a margin of safety. I am a very blocking-and-tackling kind of a thinker. I just try and avoid being stupid. And I have a way of handling a lot of problems. I put them on what I call my too-hard pile. And I just leave them there. I'm not trying to succeed in my too-hard pile."