"In the northern sea, there is a fish named Kun. Kun is so huge that its size is unknown, possibly thousands of miles long." More than two thousand years ago, the magnificent imagery depicted by Zhuangzi resonated concretely in the autumn twilight at the mouth of the Yellow River. The autumn vacation will eventually end, and the crowds will eventually disperse, but the phrase "fish swimming in the sky" uttered by the little tourists will always echo in my ears.