Earlier quoted context omitted.
I have a cunning plan: Sneak as many Brits into Hollywood as possible, and have them slip in as many British references into American films as they can. Over time, they'll effectively BECOME British, and Robert's your father's brother! Just whatever you do, don't mention the taxes! I did once, but I think I got away with it...
I experienced this. I only lived in the U.K. for 6 months, but the number of chiefly British phrases/words/idioms that nestled their way into my way of speaking and stayed (20+ years on) was interesting and somewhat surprising. For example, I never said "supposed to" again — "meant to" has always sounded and felt so much better. Similarly, "can't be bothered/asked" often exactly describes the situation in a way that…
What you heard wasn't what they were saying.