我们不是在做产品，我们是在做服务。

数学的目标是理解我们观察到的现象背后的结构。

不要让拒绝定义你的道路。

There is no point treating a depressed person as though she were just feeling sad, saying, 'There now, hang on, you'll get over it.' Sadness is more or less like a head cold- with patience, it passes. Depression is like cancer.

死者从未真正离去，他们只是改变了形态。

你遇见的每一个人，都对某些你一无所知的东西了如指掌。你要做的就是去发现那是什么东西，当然那并不会很明显。