Your moral principles and your economic interests won't always be aligned. What you do when they're not is a test of character. - Paul Graham

I suspect one of the rarest skills is to have any sense whatsoever of how different things were in the past. I believe it's as rare as being able to solve hairy integrals, but we don't realize that because there are so few explicit tests of it.

The danger of working in secret is inversely proportional to the simplicity and precision of the test. It would be safe to work in secret for a year on a new rocket engine. But if you work in secret for a year on a new social network, it will probably be a flop.

It doesn't feel laborious to go over every sentence in an essay 50 times. The mistakes in early drafts irritate me so much that it would be hard to stop trying to eliminate them.