The mind grows by exercise, not by passive absorption.

The most sustainable product is the one that already exists.

The most important thing is to keep thinking, keep questioning.

The intellectually sophisticated person is indifferent to all genuine individuality, because relationships and reactions result from it which cannot be exhausted with logical operations.

Why worry? If you’ve done the very best you can, worry won’t make it any better.

我已经履行了我的职责。我证明了庞加莱猜想，我在数学上没有什么可做的了。