We were having the same issue with my 9 year old nephew. What helped us is to show him pictures of other kids his age in kilts, and also pictures of "warriors" (think Brave Heart) in kilts, and things like that. Not sure if this would help or not. My 4 year old is excited to wear a "Scotland kilt" just like Daddy. Guess he's still young enough to not question it, lol.