You make a lot of decisions based on how you think they will make you feel in the future.....
The evidence is pretty clear, though, that big positive and negative events don't have an enormous impact on people's happiness.......
The finding, that we believe future positive and negative events have a bigger impact on our future happiness than they do, is called an affective forecasting error. One thing about these errors that is not well understood: Why don't they go away over time?


The article