Thats exactly right. I've noticed it with my own kilt experience, and you can even notice it if you look at other people in different types of clothes.

For example, next time you are somewhere teens hang out notice the goth kids. Sure they look stupid, but for some what they are wearing just seems natural. For others you can tell its a costume, a personna they are adopting for the moment.

For me, when I meet another kilt wearer at a festival or fair I can usually tell if they are daily wearers or just for special occasions. The daily wear guys just have their kilt on. The ones who just break them out for special occassions HAVE THEIR KILT ON! Even if they arent worried about being made fun of, they still arent entirely comfortable and you can tell the garment is foremost on their mind at all moments.