The idea that a bell rings to signal when investors should get into or out of the stock market is simply not credible.

Art is not about perfection. It’s about expression.

Old minds are like old horses; you must exercise them if you wish to keep them in working order.

Those who deny freedom to others, deserve it not for themselves; and, under a just God, can not long retain it.

坚持是数学研究的关键，许多伟大的成果来自于长期的奋斗。

唯一的力量就是说"不"的力量。