I don't believe in luck, I believe in preparation meeting opportunity.
我不相信运气，我相信准备遇到机会。
Actions are right in proportion as they tend to promote happiness； wrong as they tend to produce the reverse of happiness.
The real challenge in computer science is not to write programs, but to understand the nature of computation.
Writing is a way of fighting against the absurdity of life.
The value of an economic model lies in its ability to explain and predict.