真正的力量在于控制自己，而非他人。

译文：纵欲放荡、消极怠慢就不能勉励心志使精神振作，冒险草率、急躁不安就不能修养性情。

To me, fearless is not the absence of fear. It's not being completely unafraid. To me, fearless is having fears. Fearless is having doubts. Lots of them. To me, fearless is living in spite of those things, every single day.

数学家的工作永远不会完成；总有新的问题需要探索，新的谜团需要揭开。

老年并不有趣，直到你真正到达那个年纪。