"I don't think they realize there are more than the one of us they encounter."
You know... I think you're right on about that. I think that most people in the states see a kilted guy as a sort of singularity outside of anyting other than Highland games, or perhaps a ren-faire (not opening that can of worms here).
LOL *** THE INTERNETS EXIST! Yeah, perhaps some people have never heard of message boards or something.

Why I wear the kilt:
Comfort, heritage. Simple.
If I want a convenient excuse, it's usually something silly off the top of my head. Like someone else said "It's (insert day here)"

I loved the comment about claiming to be a radically different ethnicity than you are (like a Caucasian claiming to be Vietnamese), that really would toss someone for a serious loop, as I honestly don't think that they're expecting something like that.

Of course, I hate the notion that people think you need to justify (to them) why you are doing a particular thing. You don't owe ANYONE an explanation why you are wearing a particular article of clothing (well, at least not some random stranger... I can thing of a few scenarios where one might be concerned about someone close).

There's an answer: Why do you think I owe you an explanation for why?