I'm not entitled to have an opinion unless I can state the arguments against my position better than the people who are in opposition. I think that I am qualified to speak only when I've reached that state.

Finding a single investment that will return 20% per year for 40 years tends to happen only in dreamland. In the real world, you uncover an opportunity, and then you compare other opportunities with that. And you only invest in the most attractive opportunities. That's your opportunity cost. That's what you learn in freshman economics. The game hasn't changed at all. That's why Modern Portfolio Theory is so asinine.

What good is envy? It’s the one sin you can’t have any fun at.

With Congress and the S.E.C. so heavily peopled by lawyers, and with lawyers having been so heavily involved in drafting financial disclosure documents now seen as bogus, there was a new "lawyer" joke every week. One such was: "The butcher says 'the reputation of lawyers has fallen dramatically', and the check-out clerk replies: "How do you fall dramatically off a pancake?

Of course the self-serving bias is something you want to get out of yourself. Thinking that what's good for you is good for the wider civilization and rationalizing all these ridiculous conclusions based on this subconscious tendency to serve one's self is a terribly inaccurate way to think.

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.

Intelligent people make decisions based on opportunity costs.