On pivoting: "If you're not stubborn， you'll give up on experiments too soon. And if you're not flexible， you'll pound your head against the wall and you won't see a different solution to a problem you're trying to solve."
即使做很困难的事情，也一定能够达到目的，没听说过想达到自己的愿望，而能回避困难的。遇事不怕事，人是要有些胆量的。拿得起、放得下、有担当，不逃避，才能直面凛冽的人生。
A mathematician's work is never done; there are always more problems to solve.