I work with kids and costumes (Costume section and fitting room at a costume store) so every day is full of adorable kids and costumes stories.
Yesterday a little boy tried on a Batman costume and ran around the store for 20 minutes showing EVERYONE that he was Batman. When his mom lost him, we paged him to the front, "Will Batman please come to the front desk?"
His reaction was pretty adorable
All kids are cosplayers at heart.