Cosine: The exact moment Jeff Bezos decided not to become a physicist

Because I wanted to be a theoretical physicist, and so I went to Princeton. I was a really good student. As I pointed out already, I got eight pluses on almost everything. I was in the honors physics track, which starts out with, you know, 100 students, and by the time you get to quantum mechanics, it's like 30.

So I'm in quantum mechanics; I think this is like junior year. I've also been taking a bunch of computer science classes and electrical engineering classes, which I'm also enjoying. And I can't solve this partial differential equation—it's really, really hard. I've been studying with my roommate Joe, who also was really good at math, and the two of us worked on this one homework problem for three hours and got nowhere.

We finally said—we looked up at each other over the table at the same moment—we said, "Yo Santa!" Because Yo Santa was the smartest guy at Princeton. We went to Yo Santa's room, and he was Sri Lankan. In the Facebook, which was an actual paper book at that time, there were—his name was three lines long, because I guess in Sri Lanka, when you do something good for the King, they give you an extra syllable on your name. So he had a super long last name—the most humble, wonderful guy.

We showed him this problem, and he looks at it. He stares at it for a while and he says, "Cosine." I'm like, "What do you mean?" He's like, "That's the answer." And I'm like, "That's the answer?" And he's like, "Yeah, let me show you." So he brings us into his room, he sits us down, he writes out three pages of detailed algebra, everything crosses out, and the answer is cosine.

I said, "Listen, Yo Santa, did you just do that in your head?" And he said, "No, that would be impossible. Three years ago, I solved a very similar problem, and I was able to map this problem onto that problem, and then it was immediately obvious that the answer was cosine." That was an important moment for me because that was the very moment when I realized I was never going to be a great theoretical physicist. [Applause]