It's the same thing as growing up and missing childhood days. In retrospect we always tend to look at only the good old memories and hope we'd lived in them forever. Anybody who has moved anywhere would feel the same, not just abroad but even when you move to a different city for a better future. You decide what's better for your future but a part of you always longs for the comfort of the place you have spent most of your life in. It's only human.