William McRaven: The young men that join the SEALs or the Army Green Berets or the Rangers, there is a sense of adventure about them and there is a sense of confidence about them. Ninety-nine percent of the people that come through training have played in some sort of sport. So we had, in my class I had a lot of swimmers and rugby players and water polo players and football players. And so you have a level of confidence, you have a level of a sense of adventure.  So you come into a situation like that and there is — and of course when you’re young you’re a little bit cocky.  You tell yourself, “There’s nothing I can’t do. I am the best at what I’m doing.”  So you challenge yourself, and I think it’s true of any endeavor. So I’m not sure that there was this great strength of character. I think it was, fortunately, being young. You come in probably a little bit overconfident, but you also come in physically strong.  And you have gone through a process in high school or other places to really build up your, again, your skill set, your sense of adventure, your sense of character that allows you to get through training.