The essence of mathematics lies in its freedom.

If you are simple, the world will be simple to you.

有时候最真实的东西反而是你看不见的。

We are all in the gutter, but some of us are looking at the stars.

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.