数学的本质在于它的自由。
The essence of mathematics lies in its freedom.
我喜欢对一堵墙说话，世界上只有它不会反驳我。
The best way to learn mathematics is to do mathematics.
Most men die at twenty or thirty; thereafter they are only reflections of themselves.
We are all going to die, and that makes us the lucky ones. Most people are never going to die because they are never going to be born.