你不需要成为每家公司的专家，甚至不需要了解很多。你只需要能够评估在你能力圈范围内的公司。

You don't have to be an expert on every company. You only have to be able to evaluate companies within your circle of competence.

不懂的公司，不碰。

If you don't understand a company, don't touch it.

没看懂的公司比较容易鉴别，就是股价一掉你就想卖，涨一点点你也想卖的那种。看懂的那种大概就是怎么涨你都不想卖，大掉时你会全力再买进的那种。

Companies you don't understand are easy to identify: when the price drops you want to sell, when it rises a bit you also want to sell. The ones you understand: no matter how much they rise you don't want to sell, and when they drop big you want to buy more.

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.