"Books are mirrors: you only see in them what you already have inside you."
数学中的每个问题都是一个等待解决的谜题，而乐趣就在于解决的过程。
The only limits are the ones you set for yourself.
Don't bend; don't water it down; don't try to make it logical; don't edit your own soul according to the fashion. Rather, follow your most intense obsessions mercilessly.
Sustainability is not an option; it's a necessity for long-term success.