When Warren lectures at business schools, he says ‘I could improve your ultimate financial welfare by giving you a ticket with only twenty slots in it so that you had twenty punches – representing all the investments that you got to make in a lifetime. And once you’d punched through the card, you couldn’t make any more investments at all. ‘ He says ‘Under those rules, you’d really think carefully about what you did, and you’d be forced to load up what you’d really thought about. So you’d do so much better.’ Again, this is a concept that seems perfectly obvious to me. And to Warren it seems perfectly obvious. But this is one of the very few business classes in the United States where anybody will be saying so. It just isn’t the conventional wisdom. To me it’s obvious that the winner has to bet selectively. It’s been obvious to me since very early in life. I don’t know why it’s not obvious to very many other people.