People know what they do; frequently they know why they do what they do; but what they don't know is what what they do does.

People know what they do; frequently they know why they do what they do; but what they don't know is what what they do does.

人们知道自己在做什么;他们常常知道自己为什么要这么做;但是他们不知道他们做了什么。

-- Michel Foucault 福柯