如果你想读一本书，但它还没有被写出来，那么你必须写出来。

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.

生下来就知道的人是上等，经过学习才知道的人是次一等，遇到困惑才学习的人是又次一等，有了困惑而不学习的，这是最下等的人。