True story - I’ve mentioned that in college I worked for HBO sports at Wimbledon. We were there during the 4th and one of my British co-workers was reading a newspaper and said to me, “It says here that in the US they are celebrating Independence Day today. Independence from what?”
Surprised I said, “Well… actually… YOU!”
We talked about it and a few other Brits gathered around for the discussion. None of them had ever been taught that the US had fought GB for their independence. I found that quite humorous. The few who had even thought about it just kind of thought GB and the US had amicably parted ways or something.