Keep your face always toward the sunshine, and shadows will fall behind you.

翻译：既了解敌人，又了解自己，每次作战都不会有危险。

如果你不倾听客户的声音，你就已经落后了。

"The difference between correlation and causation is fundamental in empirical work."

语言是理解世界和与他人连接的关键。