An acacia tree outside the base of the Masada.
Then I had another thought: Physics disgusts me a little bit now, but I used to enjoy doing physics. Why did I enjoy it? I used to play with it. I used to do whatever I felt like doing—it didn’t have to do with whether it was important for the development of nuclear physics, but whether it was interesting and amusing for me to play with. When I was in high school, I’d see water running out of a faucet growing narrower, and wonder if I could figure out what determines that curve. I found it was rather easy to do. I didn’t have to do it; it wasn’t important for the future of science; somebody else had already done it. That didn’t make any difference: I’d invent things and play with things for my own entertainment.
—Richard Feynman, Surely You’re Joking, Mr. Feynman!
One of the things that shines through in Feynman’s memoir is just how much pleasure he took in his work. He took it seriously, he dedicated himself, but he never lost the joy of figuring things out.
Actually, to be more accurate, at one point he did.
After the successful detonations of two atomic bombs—which Feynman had helped build—and the Allied Victory during World War II, he returned to Cornell. To hear him tell it, at that time in his life, he wasn’t finding any more pleasure in physics.
And what happened?
He stalled. One of the most brilliant minds of his generation, a man who would go on to win a Nobel in physics, and he was essentially on pause.
But eventually he got out of it. How? He bucked the pressure. He went back to doing things that interested him. “Why did I enjoy it?” he asks himself. “I used to play with it.”
If you pay attention to stories about great men, you’ll see this pattern all the time in their behavior. It’ll take different labels—something like a “willingness to experiment,” or the ability to embrace “the beginner’s mind”—but really it’s all the same. Because at their core, Feynman’s playfulness, or similar labels for it, are just a form of humility. The kind which you can lose if you aren’t careful, and if you don’t take time to remind yourself of it.