Rationality is not just something you do so that you can make more money, it is a binding principle. Rationality is a really good idea. You must avoid the nonsense that is conventional in one's own time. It requires developing systems of thought that improve your batting average over time.
Charlie MungerHere's one truth that perhaps your typical investment counselor would disagree with: if you're comfortably rich and someone else is getting richer faster than you by, for example, investing in risky stocks, so what?! Someone will always be getting richer faster than you. This is not a tragedy.
Charlie Munger