Especially working in infectious disease, it's very interesting because these infectious diseases, these agents, they evolve over time. So it's very much an arms race and understanding how each changes to protect itself and to continue. And so it's very much this puzzle-solving but with this great urgency and importance in what you find.

At 9, I think I had really gotten into tennis. I liked writing short stories; I loved solving math problems. I was learning a little piano, and I was collecting Garbage Pail Kids cards.

The process of discovery in my field is very incremental. But there are moments when you realize you know something about the world nobody else knows. That's extraordinarily exhilarating.

You get these moments of thrill. There you are, at 3:00 in the morning, and you know something about how we evolved that nobody else in the world knows. It's a thrill of discovery. You make this breakthrough, and you find something. It's this wonderful, wonderful scavenger hunt when you got to the end. It's just so great to be a scientist.