According to Nobel prize-winning psychologist Daniel Kahneman, we humans are very poor decision makers when it comes to our own happiness. The problem begins with language. We use the word happiness, Kahneman says, to refer to two very different and often mutually contradictory phenomena: the mood of the moment and our overall life-satisfaction. The former is an evanescent and notoriously unreliable gauge of the latter. Example: the joy of buying a new car vs. the subsequent, ongoing annoyance of paying the monthly bills.
Kahneman’s decades of cognitive research, much of it done in collaboration with longtime colleague Amos Tversky, has shown that humans are subject to what he calls a “focusing illusion.” We focus on the moment, overestimating the importance of certain factors in determining our future happiness and ignoring the factors that really matter.
For this reason, people commonly assume that moving to a warmer climate will make them significantly happier.