Never close your lips to those whom you have already opened your heart.

数学不仅仅是关于数字、方程、计算或算法：它是关于理解的。

最古老、最简短的词语——'是'和'否'——是需要最多思考的。

The only thing I know is that I paint because I need to, and I paint whatever passes through my head without any other consideration.

People who decry the fact that businesses are in business "just to make money" seldom understand the implications of what they are saying. You make money by doing what other people want, not what you want.