That's indeed a very hard question to answer. Mankind's curse is that no-one is ever truly happy with what he or she has. Of course, you can be worse or better off but I often see people with a lot less being a lot happier than those who have everything.
Take my boss for example. He has a beautiful Polish wife (imported
), a son, a daughter and a stepdaughter. He lives in a beautiful and large house, drives a big car, has his own successful company yet he rarely smiles. All he does is worry and worry and complain and aggravate himself. He's never happy even though his company is growing and flourishing.
Even his son and daughter aren't better off - who would want a father like that? Never home and when he is, always busy, stressed out.