We don’t spend any time looking back at Berkshire. There’s so much to look forward to that it just doesn’t make sense to look behind. You can only live life forward. You can learn something from the mistakes (preferable other people’s mistakes), but the big thing to do is to stick with the businesses you understand. You want your decision making to be by looking in the mirror – stay in your circle of competence. You should be able to explain why you are buying a stock: “I am buying 100 shares of XXX, because….it is your responsibility to know. There is got to be a reason you buy a business. There is got to be a reason you buy a stock.