What makes us happy?

For our final project we are to find a theme on TED that interests us and narrow that down to a good topic to do a project on. The theme that grabbed me is what makes you happy. Earlier in the year I had one post on happiness and the video that I blogged about I really enjoyed. So, I thought this would be a great theme. Then comes the narrowing down to a topic. What makes you happy, that's a pretty specific thing if you ask me, but lets go smaller and do my final project an happiness in general. What exactly is happiness? Is it just a feeling or something you can accomplish? Happiness is something that everyone wants, but I've never really thought about it much and think it would be an interesting research topic. I have a feeling it will be hard to find the information I need, but knowing this theme is on TED will probably benefit me in the end. Where did the word happiness come from? Does it have a deeper meaning then just a good feeling you get?  So many questions are rolling around in my head, I can't wait to get started. In the end I want to be a happiness expert and be able to answer the question what is happiness, with an in depth, intelligent, passionate answer.