I never tell people that I am trilingual. I will sometimes admit that I can speak three languages, but I prefer saying I've "learned" German and Arabic. But I'm not good at learning languages. Instead, I'm good at surviving the learning of languages. I can pick up grammar patterns no problem - when it comes to vocabulary, it's like trying to memorize the water dripping out through cupped hands.
And yet, I know that when I speak German, I become a different person. Well, somewhat different. Because in Germany, people don't really wait in lines for food. There is no pausing to think about your order at the check-out window. You either order, or the next person orders and pays while you're still wondering what you did wrong in the process of trying to get food. So when I speak German in Germany, I tend to be a bit more assertive. Well, at least when it comes to ordering food.
For me, phenomena like this have always seemed like simple "cultural differences." Kind of like the anecdote of the American astronaut who went hungry while staying aboard Russia's Mir. Unaccustomed to the Russians and their ways of simply grabbing food, he wasn't getting enough to eat. Finally, one day he just gave in to rudeness and starting grabbing food himself. His Russian colleagues, noticing the change, only asked what had taken him so long.
The problem, though, is that these "cultural differences" are more the result of mass perception rather than individual reality. There are plenty of Americans who never wait in line for food - it's just that I'm not usually among them. The problem for teachers and scholars, though, is that one person's experience creates a cultural reality.
(I'll post more soon. --Ryan)