做数学就是探索一个思想的宇宙，唯一的限制是你的想象力。

The only way to get through life is to laugh your way through it. You either have to laugh or cry. I prefer to laugh. Crying gives me a headache.

You cannot step into the same river twice.

翻译：鼓励人们坚持不懈地努力，最终会取得成功。