Why is the Stone Monkey never satisfied in the novel, Monkey?

The Stone Monkey is never satisfied because he always wants more. He wants power, and the reader sees that the Monkey wants to be king of the monkeys. When he gains that, then he wants to be Immortal. When Monkey achieves this, he wants to be named the King of Heaven. Even after Monkey is placed under the Mountain of the Five Elements for five-hundred years, it is clear he hasn't truly repented of his nature.