Laughter and tears are both responses to frustration and exhaustion. I myself prefer to laugh, since there is less cleaning up to do afterward.

无法摆脱自己的自由。

The art of doing mathematics consists in finding that special case which contains all the germs of generality.

如果你一心为了讨喜，那你就要准备随时随地的屈就，并且你会一事无成。