" In The Tao of Warren Buffett, Mary Buffett and David Clark explain: “Warren decided early in his career it would be impossible for him to make hundreds of right investment decisions, so he decided that he would invest only in the businesses that he was absolutely sure of, and then bet heavily on them. He owes 90% of his wealth to just ten investments. Sometimes what you don’t do is just as important as what you do. "

― Greg McKeown , Essentialism: The Disciplined Pursuit of Less