So any student who wants to get into psychology, right now the students are like lemmings. They say, “Well, it’s popular to study brain science, I’ll do that.” Or, “It’s popular to do neural networks; I see 30,000 people doing it, it must be good.” And my advice is if a lot of people are doing it, don’t waste your time.

The most important piece of advice that I could give them is to take advantage of the tremendous reservoir of knowledge that’s out there today. Spend some time learning how the world has evolved. There are a lot of good lessons in history, and other peoples’ experiences in the past, that could be exactly the solution to the problem you’re looking for.

Don't screw it up. Don't take it for granted. Try new things, even if you're old. Do the right thing, because if you do the right thing, the money will follow. Decide what you stand for. Finally, don't worry about being cool—be warm.

Having advanced well beyond what the French call "a certain age," I am often asked to convey to younger people helpful advice and counsel. So I will open these remarks with the best advice I ever received. The advice, which I have several times shared with others, was given to me by my mother-in-law on my wedding day. She had a prescription for a happy, enduring marriage: "It pays," she said, "it pays sometimes to be a little deaf."

When we started Airbnb, no one wanted to invest. I felt like a failure so many days. It was small, it wasn't growing... A sane person probably would have quit. But we kept going through obscurity, through rejection. We couldn't raise money — but over time, it started growing.

We need to have mentors. I think I've always been pretty shameless about seeking out people much smarter and much more experienced than me from the very beginning. Michael Seibel and other people. And the more successful I got, the more leaders I started seeking out, whether it was investors, or Sheryl Sandberg at Facebook, or I got the opportunity to spend time with Warren Buffett and he became a close mentor of mine.