The difference is that I have accepted my place in life,
and ye shall forever be downtrodden as a result.
While I understand what you're trying to say to the parent and even, to an extent, agree with you the other side of the argument is that if you don't learn to accept where you are in life then you can never be content. I would imagine the parent is probably referring to having found a place in life that they are happy with. That's kind of an important bit of wisdom since for many people being at the "top" doesn't lead to happiness.
For an example I'm at the top of my game, but not at the top of earnings. Still, I make plenty of money, have no problem paying bills, buy anything I want, and do whatever I want (within reason). I don't let people walk over me but I don't need to walk over them, either. I find most people would be a lot happier if they'd take a few moments to realize that they don't actually want to be at "the top," it's just our media machine that blasts you with that.
Of course I could be wrong, I don't know for certain, none of us do. Maybe the parent's just a slacker.