It all depends on individuum. I moved two countries to-date that couldn't be more culturaly and language different. I did learn languages before I moved though. Both me and my wife adapted within a week.
The difference in culture may be there, but it is as big and sometimes much bigger between citys and countryside, regions and social classes. It may be a factor but the as I think main reason most people do not move is not any barrier in the different style of life but more so the fact of moving, getting a way from your sorroundings, friends, family etc. altogether
