When you do something best in life, you don’t really want to give that up – and for me it’s tennis.

自然权利...是每个人都有权利按照自己的意愿使用他自己的力量来维护自己的本性。

Abstraction is the key to mathematics.

Failure is the best teacher. You learn by making mistakes and figuring out how to correct them.

Diplomacy is the art of restraining power.

唯一确定的是不确定性。