Essentially, you subconciously collect "likes" about each place where you spend a sufficient amount of time.
The food in this place, the coffee shops somewhere else, a street market culture here, the women/men there. A language, the climate, pace of life and attitudes from other places.
With time, the mind constructs its own personal Shangri-la (which contains _all_of these things) and you, explicitly and/or implicitly, spend the rest of your life dissatisfied with the delta on your actual experience.
In practice, for me this has been more of an "ah... that's happening, heh" thing that I observe going on in the mind rather than a difficult-to-live-with curse.
I'm curious, however, what the effects will look like another 10 or 20 years in. I suspect it could grow worse with age as we are able to travel and do less? That's hopefully just a matter of managing perspective, though.