一纸文凭不见得就可以造就一个人，正如同牢狱生涯也不见得会打垮每一个人。

The unity of mathematics is not imposed but discovered.

You can't let praise or criticism get to you. It's a weakness to get caught up in either one.

"The books we need are the ones that read us."

Sustainability isn't a choice—it's a responsibility we owe to the next generation.