I found this recent TED talk from Daniel Kahneman (Nobel laureate, psychologist, and founder of behavioral economics) to be quite insightful. He talks about how, when it comes to happiness, we really have two selves — our experiencing selves, and our remembering selves — and they perceive happiness quite differently.
I found the ramifications of the remembering self to be most interesting. The remembering self, for instance, remembers the major events and endings most – so if we have a great experience that ends badly, it is the end that we remember. He gave the example of someone listening to a wonderful symphony for 20 minutes, that then ended with a terrible screeching noise. So while the experiencing self was happy and enjoying the music during those 20 minutes, all the remembering self remembers is the bad ending, and the memory is ruined. Translating to user experience, I think this shows how important it is to design for the entire end-to-end experience, as one slip at the end may forever change a user’s perception of a service.
My other favorite comment of his: we don’t think of the future as a string of experiences, but only as “an anticipated memory.”