时间的主要美在于你不能提前浪费它。下一年、下一天、下一个小时都为你准备着，完美无瑕，仿佛你一生中从未浪费或误用一刻。如果你愿意，每小时都可以翻开新的一页。
The chief beauty about time is that you cannot waste it in advance. The next year, the next day, the next hour are lying ready for you, as perfect, as unspoiled, as if you had never wasted or misapplied a single moment in all your life. You can turn over a new leaf every hour if you choose.
"You do not just wake up and become the butterfly—growth is a process."
数学不知道种族或地理边界；对于数学来说，文化世界是一个国家。
勤勉：不要浪费时间，只做有用的事情，戒除一切不必要的行为。
