The idea of excessive diversification is madness. Wide diversification, which necessarily includes investment in mediocre businesses, only guarantees ordinary results.
Charlie MungerA different set of incentives from rising in an economic establishment where the rewards system, again, the reinforcement, comes from being a truffle hound. That's what Jacob Viner, the great economist called it: the truffle hound - an animal so bred and trained for one narrow purpose that he wasn't much good at anything else, and that is the reward system in a lot of academic departments.
Charlie Munger