is Positive Psychology.
I got into it in a roundabout way: caught Jonathan Haidt's TED talk and started looking at his other stuff. Read everything he had on the web for his book 'The Happiness Hypothesis', including quite a few complete chapters, then bought the book. (Which just goes to show the value of making things available for free and then people buying them...)
Once I finished reading THH closely, I requested the two Martin Seligman books our library has: 'Learned Optimism' and 'Authentic Happiness'. Seligman is maybe the leading figure in the field. I'm partially into both of these books (one is audio) and as interested as ever.
Then I found out my friends, Kurt and Kathi, are into the field through a different entree, Tal Ben-Shahar, who teaches the biggest class at Harvard and it's on Positive Psychology. His website is not as rich as I might wish, but his book's selling like hotcakes ;-)
It does look, however, like all of his lectures from the course have been put up on YouTube. The first one is here. Not sure if I'll watch them all, yet. That would be a lot of time, and it's a pretty inefficient medium.
What's my motivation? I am not as happy as I should be. I have a great life in most ways. But my mind has some pessimistic function that is working against me. I am hoping that I'm going to be able to recalibrate.