"You can't go back and change the beginning, but you can start where you are and change the ending."
I'm not afraid of dying, I'm afraid of not trying.
Mathematics is the art of giving the same name to different things.
行为主义者放在自己面前的规则或衡量标准总是:我能否用"刺激和反应"来描述我所看到的这一行为?