The history of mathematics is a history of human curiosity and ingenuity.
数学的历史是人类好奇心和创造力的历史。
最有趣的艺术是提出问题的艺术。
If you're not stubborn, you'll give up on experiments too soon. And if you're not flexible, you'll pound your head against the wall and you won't see a different solution to a problem you're trying to solve.
"The wise man learns more from his enemies than the fool from his friends."