Rigor in proof is what separates mathematics from all other sciences.
Better never means better for everyone... It always means worse, for some.
The only limit to our realization of tomorrow is our doubts of today.
The striving to find a meaning in one's life is the primary motivational force in man.
当你不再感到伤心的时候(时间会冲淡一切伤痛),你就会因认识我而感到心满意足。你是我永远的朋友。将会和我一起欢笑。为了欢乐,你会经常打开窗子……
过去是幽灵,未来是梦,现在只是转瞬即逝的瞬间。