I don’t count my sit-ups, I only start counting when it starts hurting.

Language is a skin: I rub my language against the other. It is as if I had words instead of fingers, or fingers at the tip of my words.

The only thing worth writing about is the human heart in conflict with itself.

系统辨识是从观测到的输入输出数据中建立动态系统数学模型的科学与艺术。

译文：立下难以实现的志向，才能吃别人不可能吃的苦，做别人不能做的事，千秋功业，才有得指望；对人对事若发现错误而不忍心去指责、纠正，那么必然会因为不忍心去说而造成祸害。

世界的历史是各民族交融的历史。