The east coast/west coast is super striking. A few American friends were surprised when I told them I thought East/West coast divide was wider than e.g. NY/France, culture-wise. New York always felt like a more culturally diverse, bigger, English speaking Paris.
When I am in Japan, there is an obvious "this is not Kansas anymore" aspect. I love it, I lived there > 10 years but I don't need any effort to know I am like a fish out of the water.
On the other hand, California or Texas are still just unsettling, in an "uncanny valley" / twilight zone kind of way. Everything is "almost" the same, but yet so many small things that add up to a strange feeling. I guess American from a western culture background would feel the same when coming to Europe ? Not sure.