I remember first hearing the word "bumbershoot" in an episode of Frasier, used as an example of a ridiculous Britishism, and being very confused, as I'd never encountered it, despite living in Britain all my life. After some research revealed it was actually American slang that had become incorrectly thought to be British, I felt oddly offended.
To be honest though, as the British and American entertainment worlds have merged over the past couple of decades, I've found myself using more and more Americanisms, and I've kind of made my peace with that. The English used in TV and film represents the language in its most modern form, and, increasingly, opposing "Americanism" also means opposing the progress of culture, and the influence of minorities and immigrant groups, and I don't want to be that kind of stuck-in-the-mud, so I'm trying to just relax and accept linguistic progress in whatever form it takes.
To be honest though, as the British and American entertainment worlds have merged over the past couple of decades, I've found myself using more and more Americanisms, and I've kind of made my peace with that. The English used in TV and film represents the language in its most modern form, and, increasingly, opposing "Americanism" also means opposing the progress of culture, and the influence of minorities and immigrant groups, and I don't want to be that kind of stuck-in-the-mud, so I'm trying to just relax and accept linguistic progress in whatever form it takes.