What’s something that’s normal in the UK but weird elsewhere?

I'm Scottish. We don't have separate hot and cold taps in modern houses. But it's interesting. The reason for separate hot and cold taps is due to preventing the spread of legionaries disease. The cold water tap came from the mains, but the hot water came from a water heater usually in the loft, or attic. This was to provide pressure. They were separate to make sure that you always drank safe water. It's fine to mix the two water sources as long as you don't give the bacteria time to multiply. That really means less than about a metre and a half of length of mixed water. The mixer tap prevents all of that. The hot water is hot and the cold water is cold until it meets. The fact that the UK still has separate taps is because it had hot and cold water before many countries and because it figured out that legionnaires disease was a potential problem. But today, every tap in my house mixes water just like anywhere else in Europe.