Have you ever felt envy? I bet you have. It doesn't feel good, does it?
What can your envy tell you about yourself? Logically, it means the other person has achieved something you want too. Now, if we are not talking about envying someone winning the lottery, but about their achievements... Perhaps deep in your heart you know you just might have what that other person has, if you had done something about achieving it. And the longer you have postponed doing that something, the more the envy hurts.
We are taught envy is of no use, and will only make you bitter. I'd say quite the opposite, if we approach envy from another angle. If we let it show what we want deep inside, and start doing something about it, envy can be a stepping stone to a better life.
Next time when you feel envy, why not write down exactly why you feel that way. And then write: make mind maps, draw charts, write sentences... all about how you could take your first step towards achieving that thing you feel so strongly about. Plan your steps, and start by taking the first one.