oh man, when others are chill about it, it's always fun to learn what food traditions are less universal than you thought they were!
A few months ago I was talking about tv dinners in a discord server and two of our international members -- one from the netherlands, one from australia -- asked what on earth I was talking about. "Oh!" I said, "that's probably a US phrase -- it's those little frozen dinners you put in the microwave"
".....What?" they asked. So I googled a picture of what I was talking about, assuming I just didn't know what they were called outside the US, and posted in the chat.
And neither of them had ever seen anything like that.
The next day I went grocery shopping and took photos of the frozen food aisle to show them just how pervasive frozen dinners are here. They were flabbergasted. They'd never heard of these before. How can you eat something like that???
The discovery that Frozen TV Dinners is not a universal food was a fascinatingly weird experience for all involved xD
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anyway I don't like ketchup or hotdogs so I can't really contribute on that front, but putting ketchup and mustard on a hotdog is pretty standard in my neck of the woods!