In my travels, I learned very quickly not to let that bother me, or else I would have gone nuts. I mean, the number of times somebody acted like I was an insane person because I started to eat X food with my hands instead of silverware, or silverware instead of hands. ("But in the last country I was in...!")

Fact is, you're the one choosing to be aware of and experience different cultures and travel, but they're not making that choice. And I had to conclude that they shouldn't need to make that choice if they don't want to. So I just sucked it up and would go along with the joke, "yeah us foreigners are such weirdos, ha!"