We spend a lot of time and effort trying to figure out who's going to be a good NFL quarterback, and we do a very bad job of it. We don't really know. And we also spend a lot of time trying to figure out who will be a good teacher, and we're really bad at that too. We don't know if someone is going to be a good teacher when they start teaching. So what should we do in those situations in which predictions are useless?

Six degrees of separation doesn't mean that everyone is linked to everyone else in just six steps. It means that a very small number of people are linked to everyone else in a few steps, and the rest of us are linked to the world through those special few.

A radical and transformative thought goes nowhere without the willingness to challenge convention.

If people disobey, don't ask what is wrong with them, ask what's wrong with their leaders.

I would say first of all, anyone who wants to challenge the status quo always gets that response. Ninety percent of the time, that's just bull. That's just the way in which people choose to prop up their own privilege or their own particular position. So mostly I shrug it off.

Our intuitions, as humans, aren't always very good. Changes that happen really suddenly, on the strength of the most minor of input, can be deeply confusing.

There's no idea that can't be explained to a thoughtful 14-year-old. If the thoughtful 14-year-old doesn't get it, it is your fault, not the 14-year-old's.