Are you saying that only weird American adults enjoy dressing up and pseudo pretending to be figures from history, characters in science fiction, etc.?

Not if you're going to contradict me!

But I'm intrigued by "pseudo pretending" - which I think captures something that involves more effort and dedication than just dressing up for a lark (something people do here at the drop of a hat), but isn't necessarily about getting it right either. It's that middle-ground where, perhaps, RenFairistas rub shoulders with Xena, Frank N. Furter and spooky Morris.