The key thing that everybody needs to understand is that mother nature does not care if you're happy. Mother nature wants to make you fit in the reproduction game. The way that you do that is by being successful in money and power, pleasure and admiration of other people. And so we have a process called homeostasis in which our satisfaction drives us to get more stuff but we can't maintain the joy from getting these things more than a minute or a day or a week. That's why we call the hedonic treadmill the treadmill of running and running and running, and out sized people on this.