"If water is not piled up deep enough, it won't have the strength to bear up a big boat. Pour a cup of water into a hollow in the floor, and bits of trash will sail on it like boats. But set the cup there, and it will stick fast, for the water is too shallow and the boat too large. If wind is not piled up deep enough, it won't have the strength to bear up great wings. Therefore when the Peng rises ninety thousand li, he must have the wind under him like that. Only then can he mount on the back of the wind, shoulder the blue sky, and nothing can hinder or block him. Only then can he set his eyes to the south."
~ The Complete Works of Zhuangzi, translated by Burton Watson
