Natural experiments are a powerful tool for understanding causal relationships in the real world.
我有一个非常简单的想法，如何变富。第一，花得比赚得少；第二，明智地投资差额。
Every observation we make is a step closer to unraveling the mysteries of the universe.
The secret of happiness，you see，is not found in seeking more，but in developing the capacity to enjoy less.
释义：如果不能长久地保持其君子之德，就可能蒙受羞辱。
The past is a place we can visit but never stay.
"I am not interested in the psychology of characters, but in the psychology of situations."