I got quite nice results in my one-question studies, but never wrote up any of the work, because I had set myself impossible standards: in order not to pollute the literature, I wanted to report only findings that I had replicated in detail at least once, and the replications were never quite perfect. I realized only gradually that my aspirations demanded more statistical power and therefore much larger samples than I was intuitively inclined to run. This observation also came in handy some time later.

In the end, I had to pay $3.3 million dollars to buy back that 90%.

Day one of my first job out of college, my boss found out that I didn't know how to enter data into Lotus 1-2-3. That's a spreadsheet—ask your parents. His mouth dropped open and he said, ‘I can't believe you got this job without knowing that”—and then walked out of the room. I went home convinced that I was going to be fired. I thought I was terrible at everything… but it turns out I was only terrible at spreadsheets.

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.

Get on with it. But make sure you do want to do it. I think that’s the important thing, to be something that you would enjoy. If you only just go into science to get rich or to win gold medals, then I wouldn’t bother, but if you really want to enjoy yourself in the lab, then do it.