I dislike mayo. It's a combination look/texture/taste thing. When I travel overseas in countries where it's a popular condiment I lean toward choosing restaurants where there are picture menus or the food is prepared in front of me and I can point to what I want, if I don't speak the language well enough to say, "No mayonnaise." Also, certain ethnic cuisines are extremely unlikely to use mayo. My most pleasurable meal on a trip to Argentina was Jordanian!

Curiously it's also difficult to avoid mayo in the US and UK, where language barrier shouldn't be a factor. Sometimes I ask, "What's on this sandwich?" and mayo isn't listed as an ingredient but is added anyway. Or I order a sandwich "plain, mustard and onions only" and it comes with mayo and maybe one or two other surprise toppings, too. There have also been multiple times I've told a food worker (who speaks English), "No mayo, please," only to watch him/her pick up the paddle 1 second later and absolutely slather my sandwich with the stuff.