Charlie Munger: There's an old saying, "What good is envy? It's the one sin you can't have any fun at." It's 100% destructive. Resentment is crazy. Revenge is crazy. Envy is crazy. If you get those things out of your life early, life works a lot better.
Warren Buffett: Temperament is more important than IQ. You need reasonable intelligence, but you absolutely have to have the right temperament. Otherwise, something will snap you.