很难想象有谁不曾一度因爱或因缺乏爱而萎靡不振。
忘记某事最好的方式就是记住它。
定义就是限制。
"The only way to learn mathematics is to do mathematics."
"Complexity theory teaches us that not all problems are created equal; some are inherently harder than others."
No man, for any considerable period, can wear one face to himself and another to the multitude, without finally getting bewildered as to which may be the true.