因果推断的本质是超越数据，询问如果我们干预会发生什么。
The essence of causal inference is to go beyond the data and ask what would happen if we intervene.
The greatest happiness is to know the source of unhappiness.
I don't know anyone who needs a strap-on more than me.
勇敢地去尝试新事物，即使一开始做得不好。