可以仕则仕，可以止则止，可以久则久，可以速则速。
应该做官就做官，应该辞职就辞职，应该继续干就继续干，应该马上走就马上走。
Never let failure define you—let it teach you.
The true way to render ourselves happy is to love our work and find in it our pleasure.
Mental activity is the organism's way of engaging with the world.
Mathematics is not just about numbers, equations, computations, or algorithms: it is about understanding.
As you grow older, you will discover that you have two hands, one for helping yourself, the other for helping others.