Zhuangzi and Huizi were strolling along the dam of the Hao Waterfall when Zhuangzi said, "See how the minnows come out and dart around where they please! That's what fish really enjoy!"

Huizi said, "You're not a fish; how do you know what fish enjoy?"

Zhuangzi said, "You're not I, so how do you know I don't know what fish enjoy?"