The ethical rule is from Samuel Johnson who believed that maintenance of easily removable ignorance by a responsible office holder was treacherous malfeasance in meeting moral obligation. The prudential rule is that underlying the old Warner & Swasey advertisement for machine tools: "The man who needs a new machine tool, and hasn't bought it, is already paying for it". The Warner & Swasey rule also applies, I believe, to thinking tools. If you don't have the right thinking tools, you, and the people you seek to help, are already suffering from your easily removable ignorance.

To some extent, stocks are like Rembrandts. They sell based on what they've sold in the past. Bonds are much more rational. No-one thinks a bond's value will soar to the moon.

If you have only a little capital and are young today, there are fewer opportunities than when I was young. Back then, we had just come out of a depression. Capitalism was a bad word. There had been abuses in the 1920s. A joke going around then was the guy who said, 'I bought stock for my old age and it worked - in six months, I feel like an old man!' "It's tougher for you, but that doesn't mean you won't do well - it just may take more time. But what the heck, you may live longer."

Early Charlie Munger is a horrible career model for the young, because not enough was delivered to civilization in return for what was wrested from capitalism. And other similar career models are even worse.

Missing out on some opportunity never bothers us. What's wrong with someone getting a little richer than you? It's crazy to worry about this.

I have a name for people who went to the extreme efficient market theory-which is "bonkers". It was an intellectually consistent theory that enabled them to do pretty mathematics. So I understand its seductiveness to people with large mathematical gifts. It just had a difficulty in that the fundamental assumption did not tie properly to reality.

Darwin paid particular attention to disconfirming evidence. Objectivity maintenance routines are totally required in life if you're going to be a great thinker.