I was super young, like maybe 4-5 or something, when my family took a short trip south from San Diego (USA) into Tijuana, Mexico since the border was right there and it wasn’t a big deal back then.

I remember seeing price tags and being really surprised… That they were in US dollars.

I don’t think I had even started school yet, but I still knew that different country = different language and different money. Not sure how people can miss that so easily.