My girlfriend warned me I'd have a hard time understanding the people in Northern UK; very broad accents where she was from. "How bad could it be" I thought.
I was getting on a plane flying directly into the Midlands to meet up with her for a vacation there. There were two women in front of me, talking. They were from some foreign country. Couldn't understand what they were saying nor what language they spoke or where they might be from.
Soon I concluded they were from South Africa because I could catch an English-derived word every other sentence amongst the gutteral, clearly teutonic, what must be Afrikaans. But eventually I realized what was really going on...
...they were from the North of England, speaking "English," and I couldn't understand more than one of every 30 words. I accepted I was gonna be so screwed without my translator!
Britons do not speak English. They will not accept that American is what the world speaks and is now English.