One widely held theory is that it's the quantity of happy moments that you have and not the quality. In other words, it's not the one big huge great thing that will make you happy. It's lots and lots of happy moments. Big or small. And since the small moments happen more easily and often than the big ones it's whether or not you appreciate and notice them that will cause you to be happy.
Happiness is a state of mind.
That's because the pursuit of things is never the end in itself. Someone who reaches a money goal will need more money the next time around. Someone who relies on their looks will always be comparing themselves to someone else who's prettier or better looking. Sure there is. Start by asking yourself these questions.