My opinion is that, for me, a kilt is neither a costume nor just an everday garment. To me, a kilt is a celebration of my heritage. I would love to be able to wear it whenever I want like a pair of pants, but it will always be something special to me, and if someone wore the Clan Donald tartan only because he liked it, I wouldn't be offended, but it does make the tartan lose its significance, especially if that person isn't Scottish or Irish. I do love to see other people getting into kilts, but they're much more than something you wear.