Every university…seem[s] to reassure you that ‘it doesn’t matter what you do, as long as you do it well.’ That is completely false. It does matter what you do. You should focus relentlessly at something you’re good at doing, but before that you must think hard about whether it will be valuable in the future.

I think anything that requires real global breakthroughs requires a degree of intensity and sustained effort that cannot be done part time, so it's something you have to do around the clock, and that doesn't compute with our existing educational system.

I'm in favor of free trade, but I think if you had to make a choice between having technological progress versus free trade, you had one or the other, you should always pick technological progress. I think it's an incredibly important variable for creating more prosperity.

For a new payment product, you always have to ask, how much better is it than the current solution? So when we started Paypal, for eBay micro merchants, it was much better than getting the 7 to 10 days process of cashing a check in the mail. When you look at stores or physical worlds, places, a lot of these places are already set up to take cash or credit card. Apple Pay may be an incremental improvement, maybe a little bit better. But when you have something that's pretty good and you go to something that's perfect, sometimes it's very hard to drive adoption because the delta is not that big.

I believe we are in a world where innovation in stuff was outlawed. It was basically outlawed in the last 40 years - part of it was environmentalism, part of it was risk aversion.

If you can identify a delusional popular belief, you can find what lies hidden behind it: the contrarian truth.

If you think your initial market might be too big, it almost certainly is.