You guys aren't giving children enough credit.

Smart kids are more intelligent than a lot of adults. Also, kids haven't had as much time for ideas to become set for them... their minds are more open. If you tell them "This isn't a skirt, it is a kilt, it is traditional clothing for Scottish men." They will usually understand. Of course there are some that won't be able to grasp the concept, but that isn't due to their age... there are adults that can't grasp the concept either.

I've had countless kids ask me about my kilt both here in Japan, and during the three weeks when I was in Alaska. Only once did the kid not seem to get it. All the other times it was like "Oh WOW, that is something I didn't know. That's cool."

When explaining it to adults it is far more common to get "Well, it still just looks like a skirt to me." or just a blank expression of their lack of comprehension.