You must understand human behavior. There are some basic models that are simple and much easier to master than quantitative mechanical theory. You have to understand something, you really need to understand.
你必须要了解人类的行为。有一些基本的模型，这些模型很简单，比数量机械理论容易掌握多了。你必须得懂一些东西，要真的懂。