Zhuangzi

If a man, having lashed two hulls together, is crossing a river, and an empty boat happens along and bumps into him, no matter how hot-tempered the man may be, he will not get angry. But if there should be someone in the other boat, then he will shout out to haul this way or veer that. If his first shout is unheeded, he will shout again, and if that is not heard, he will shout a third time, this time with a torrent of curses following. In the first instance, he wasn't angry; now in the second he is. Earlier he faced emptiness, now he faces occupancy. If a man could succeed in making himself empty, and in that way wander through the world, then who could do him harm?

Understanding that rests in what it does not understand is the finest.

Men all pay homage to what understanding understands, but no one understands enough to rely upon what understanding does not understand and thereby come to understand.