The best way to learn mathematics is to do mathematics.

"Every saint has a past, and every sinner has a future."

Good policy requires both sound theory and empirical validation.

知识的最大敌人不是无知，而是知识的幻觉。

I keep thinking about this river somewhere, with the water moving really fast. And these two people in the water, trying to hold onto each other, holding on as hard as they can, but in the end it’s just too much. The current’s too strong. They’ve got to let go, drift apart.