With so much money riding on reported numbers, human nature is to manipulate them. And with so many doing it, you get Serpico effects, where everyone rationalizes that it's okay because everyone else is doing it. It is always thus.

The possibility that stock value in aggregate can become irrationally high is contrary to the hard-form "efficient market" theory that many of you once learned as gospel from your mistaken professors of yore. Your mistaken professors were too much influenced by "rational man" models of human behavior from economics and too little by "foolish man" models from psychology and real-world experience.

Proper accounting is like engineering. You need a margin of safety. Thank God we don't design bridges and airplanes the way we do accounting.

Go to bed smarter than when you woke up.

We don't train executives, we find them. If a mountain stands up like Everest, you don't have to be a genius to figure out that it's a high mountain.

I constantly see people rise in life who are not the smartest - sometimes not even the most diligent. But they are learning machines; they go to bed every night a little wiser than when they got up. And, boy, does that habit help, particularly when you have a long run ahead of you.

Even bright people are going to have limited, really valuable insights in a very competitive world when they're fighting against other very bright, hardworking people. And it makes sense to load up on the very few good insights you have instead of pretending to know everything about everything at all times.