自然实验是理解现实世界中因果关系的强大工具。

I’m chasing greatness.

【译文】每天都学习一些自己所没有的知识、技能或所不懂的道理，每月都不忘记所学会的东西，这样就可以称为好学的人了。

What I want to talk to you about today is the difference between gifts and choices. Cleverness is a gift， kindness is a choice. Gifts are easy -- they're given after all. Choices can be hard. You can seduce yourself with your gifts if you're not careful， and if you do， it'll probably be to the detriment of your choices.

"The only thing we can be sure of about the future is that it will be different."

I'm not afraid to be alone; I'm afraid of being lonely.

不要告诉别人怎么做，告诉他们做什么，让他们用结果给你惊喜。