数学的快乐来自创造的行为，而不仅仅是结果。

译文：从深山里开采出来，经过千锤百炼，烈火焚烧也毫不在乎。就算粉身碎骨也不怕，只为在世上留下清白的名声。

Remember, if you ever need a helping hand, it's at the end of your arm, as you get older, remember you have another hand: The first is to help yourself, the second is to help others.

Psychology must be a science of description, not explanation.