我不活在过去，也不活在未来，我活在当下。

Money is not the only answer, but it makes a difference.

数学家的直觉和严谨的证明同样重要。

"Writing is an act of courage—you have to be willing to expose your deepest thoughts."

Youth is not a time of life; it is a state of mind; it is not a matter of rosy cheeks, red lips and supple knees; it is a matter of the will, a quality of the imagination, a vigor of the emotions; it is the freshness of the deep springs of life.