If you find serenity and happiness，they may be jealous；Be happy anyway。People really need help but may attack you if you do help them。

A mathematical proof is a poem written in the language of logic.

如果你发现自己在想 "咦，我的好刀呢？”或者“我的好笔在哪里？" 这意味着你有的是坏的东西。把坏的扔掉吧。