You can’t go back and change the beginning, but you can start where you are and change the ending.

I think the most important thing is to be happy and to be kind to others.

The poet is not separate from the world; the poet is of the world.

Mathematics is not about numbers, equations, computations, or algorithms: it is about understanding.

The purification of the soul is the highest pursuit in life.

数学是关于概念之间关系的科学，与这些概念的内容无关。