The best way to cheer yourself up is to try to cheer somebody else up.

我不知道是妈妈对，还是丹中尉对，我不知道，是否我们每个人都有，注定的命运，还是我们的生命中只有偶然，像在风中飘。但我想：也许两者都有吧，也许两者都在同时发生着。

The purpose of life is not to be happy. It is to be useful, to be honorable, to be compassionate, to have it make some difference that you have lived and lived well.

I want to liberate America from all the things that hold people back.

要理解宇宙，你必须理解它所用的语言，那就是数学。

如果说我看得比别人更远些，那是因为我站在巨人的肩膀上。

其实世事并无好坏，全看你们如何去想。