This is about the folly of envy. We envy someone because we think we can’t be or achieve what they are or have. Like the bird that has forgotten it can fly, we diminish ourselves when we forget that we have the ability to attain whatever goal we can imagine. But we usually don’t realize that the material accumulations someone else has is not truly what we want. What we truly want is simply to be happy. And we assume that if we have the stuff the other person has we will be. But it is only when we pursue our own nature – our personal dreams and callings (which may or may not include any physical stuff) – will we then be living a life that will be worth envying.