I would argue that a majority of the horrors we face would not have happened if the accounting profession developed and enforced better accounting.

We're guessing at our future opportunity cost. Warrenis guessing that he'll have the opportunity to put capital out at high rates of return, so he's not willing to put it out at less than 10% now. But if we knew interest rates would stay at 1%, we'd change. Our hurdles reflect our estimate of future opportunity costs.

In business we often find that the winning system goes almost ridiculously far in maximizing and or minimizing one or a few variables - like the discount warehouses of Costco.

Opportunity cost is a huge filter in life. If you've got two suitors who are really eager to have you and one is way the hell better than the other, you do not have to spend much time with the other. And that's the way we filter out buying opportunities.

Personally, I’ve gotten so that I now use a kind of two-track analysis. First, what are the factors that really govern the interests involved, rationally considered? And second, what are the subconscious influences where the brain at a subconscious level is automatically conclusions in various ways — which, by and large, are useful — but which often malfunction? One approach is rationality… And the other is to evaluate the psychological factors that cause subconscious conclusions — many of which are wrong.

Part of [having uncommon sense] is being able to tune out folly, as opposed to recognizing wisdom. If you bat away many things, you don't clutter yourself.

There's no way that you can live an adequate life without making many mistakes.