数学是人类精神最美丽和最强大的创造。
Mathematics is the most beautiful and most powerful creation of the human spirit.
You can't manage what you don't measure, and you can't improve what you don't manage.
The thing about happiness is that you only know you had it when it's gone.
一个人的出身并不重要,重要的是他成长为什么样的人。
My expectations were reduced to zero when I was 21. Everything since then has been a bonus.
You have to have fun in life, otherwise you’re just going to be miserable.