我经常看到有人跑到自己的能力圈以外去做事情，回头安慰自己的话就是'扩大能力圈'是要付学费的。

I often see people venturing outside their circle of competence, and then comfort themselves by saying 'expanding your circle of competence requires paying tuition.'

如果你不能用几句话讲清一家公司的生意，就别投它。

If you can't explain a company's business in a few sentences, don't invest in it.

了解你投资的公司，知道它在做什么生意。

Know the company you invest in and understand what business it is in.

不熟不做，知道自己不懂什么比懂什么更值钱。

Don't do what you don't know; knowing what you don't understand is worth more than what you do.