I found studying abroad at Oxford's Brasenose College to be a huge cultural shock. It didn't help that my professor, while extremely gentle, assumed that English was my second language. In some ways, though, we spoke a different English.
During my time there, my roommate, his twin brother, and I had our essays due on the same day. As a result of our incompetence at writing tutorial-style essays, we would often stay indoors without food for periods of 30 hours or more before our assignments were due. After taking a 3 hour nap, we would then wake up around dinner time and make our weekly pilgrimage to Nando's Halal Chicken. Every time we went, we were so starved we would each order a family platter, completely shocking and confusing the waiter.
When I came back from Oxford, I had lost 50 pounds in weight (from 170 pounds at the end of freshman year). My professor declared my English had "improved tremendously."