勇气不是没有恐惧，而是尽管恐惧仍选择行动。

The most sustainable product is the one that lasts a lifetime.

在计算学习理论中，挑战不仅仅是学习，而是理解学习是如何可能的。

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.

学习在于改变介于刺激和反应之间的某些中介过程。