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

There are two kinds of businesses: The first earns 12%, and you can take it out at the end of the year. The second earns 12%, but all the excess cash must be reinvested - there's never any cash. It reminds me of the guy who looks at all of his equipment and says, 'There's all of my profit.' We hate that kind of business.

Obviously, consideration of costs is key, including opportunity costs. Of course capital isn't free. It's easy to figure out your cost of borrowing, but theorists went bonkers on the cost of equity capital. They say that if you're generating a 100% return on capital, then you shouldn't invest in something that generates an 80% return on capital. It's crazy.

If you have competence, you pretty much know its boundaries already. To ask the question (of whether you are past the boundary) is to answer it.

How could economics not be behavioral? If it isn't behavioral, what the hell is it?

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.

Three rules for a career: 1) Don’t sell anything you wouldn’t buy yourself; 2) Don’t work for anyone you don’t respect and admire; and 3) Work only with people you enjoy.