Everything in this world has its own nature. Zhuangzi said, "The duck's legs may be short, but if you added to their length the duck wouldn't be happy. The goose's neck may be long, but its pain upon breaking is just as great.
物各有天性，莊子說：鳧脛雖短，續之則憂；鶴頸雖長，斷之則悲。