I went to a one day workshop this week that was given by Dr. Rick Hanson (http://www.rickhanson.net/). It was based on his book Buddha's Brain: The Practical Neuroscience of Happiness, Love and Wisdom. It was a tool mix of science and mindfulness practices. One of the things that was most valuable to me was learning more about how we are pre-wired to easily react to a negative experience because the pathways for taking in negative thoughts are simple. On the other hand, pathways for taking in positive experiences are complex, so positive thoughts and experiences need to be savored and we have to work on really taking them in so that they stick in our memory and we can use them as resources when we are struggling.
I know that I'm not usually one to dwell on things that give me the feeling of wonder, or my accomplishments or good things that have happened or how I am loved by others. In fact I often feel like something bad will happen if I do, so I notice and then quickly move on. I also often wonder why I'm always so prone to anxiety and thinking about when the "other shoe" will drop. So, the workshop gave me some scientific reasons to try to be more mindful of the positive and not just of the negative.
Apparently it only takes an extra 10-20 seconds of "marinating" to make the positive experience "stick" more. I think that's really cool because it seems really doable to notice that I'm happy and try to hang on to it for the count of 20 :)