When I was 17, I spent a year abroad as an exchange student. Before leaving, we had camps where we learned about cultural differences, adjustment issues, and all the fun stuff you experience living with a strange family in a strange country. They also talked about reverse culture shock, which happens when you go back to your country and realize that you have changed, but your country/family/school/friends have stayed the same. When I came back, it wasn´t too bad - yes, I missed my host country and my friends, but I was still very much a Norwegian.
Now, things are different, and I am experiencing reverse culture shock big time!! I try not to complain too much, but I just don´t find people very warm here. I miss small talk! I miss politeness! Europeans tend to critizise Americans for making superficial small talk but I feel that it provides the necessary grease for our societal wheels to go around! Americans in general are really good at making someone feel welcome and to show interest in other people´s lives, and I miss that. To quote Oprah: Everyone has an interesting story to tell, as long as we take the time to ask.
More to come on this... Time to warm up, July 2 is proving very cold!!