I’ve heard of a case where an American man was ranting about “why can’t they speak English” despite him being in a country where it’s not even spoken (in this case: Japan), like WTF? He’s literally in another country where a different language is spoken, isn’t that already common sense? Yes, there are (some) Americans who are like this: assuming that everyone all over the world just knows English from the get go, but that’s not always the case.
Another was when an American woman wanted to pay for the bread at a French bakery using a crisp US$20 bill, but that was not accepted since France uses Euros as their main currency. I guess it stems from the fact Mexico accept that assuming that’s universal in countries where their own currency (like the Korea uses Won, UK uses the Pound, Oman uses Rials & etc). I mean, why do (some) Americans think that every country uses US Dollars?
It’s not just Americans who do this by any means, and nor are they the worst offenders! Trust me on this, I’m British - the most wilfully parochial nation on earth.
You’ll always get the odd jerk, but mostly this stuff tends to come from a lack of travel experience more than anything else. Unless you’ve travelled, you may not even realise what assumptions you’re making about how day-to-day life works. And, well, a lot of Americans haven’t travelled much outside of the USA. (That’s not a criticism by the way - the USA is absolutely enormous and incredibly diverse, and you could spend a lifetime exploring it and not see it all.)
All that said, back in the days before dual voltage power supplies were common I did used to find it amusing watching Americans in Europe blithely plugging their electrical goods into the 220V mains and wondering why they blew up.