For me, the most striking observation was that we often spend a tiny amount of time enjoying the memory of an experience relative to the amount of time we spent experiencing it in the first place. I think that even my favourite memories would have given me no more than a few hours total enjoyment time over my lifetime. Yet Kahneman correctly points out that many of our actions are geared towards optimizing the memories we get. This seems like a cognitive bias that we would do well to overcome.