No matter how good you get you can always get better, and that's the exciting part.

The most important things are the hardest to say.

心理过程的价值在于它对有机体适应生活的效用。

大脑不是刺激的被动接受者，而是知觉的主动组织者

Happiness is like a butterfly; the more you chase it, the more it will elude you. But if you turn your attention to other things, it will come and sit softly on your shoulder.

No man's knowledge here can go beyond his experience.

What I’ve achieved in tennis is great, but who I am as a person is more important.