世间万物，唯有变化才是永恒不变的法则。
The fact that there is nothing permanent except change is a permanent theme in nature.
The value of an economic model lies in its ability to explain and predict.
I don't want to be remembered as a movie star. I want to be remembered as a good man who tried to make a difference.
Problem solving is the central activity of intelligent systems.
The only way to do great work is to love what you do.