Obviously, Thiel didn't consider himself one of those doomed lemmings. But how does one find other nonlemmings? Just look for unusual behavior. In his book, Thiel notes with pride that "of the six people who started PayPal, four had built bombs in high school." In our interview, he told me, "There is something that's always quite extreme about the personalities that go into starting a company ... Having some extreme personalities, I think, is a somewhat good thing."