You were the newest and youngest member of the Order of the Phoenix. Siruis Black and the others where also training you to be an Auror. One day, he discovers your regression. He's determined to make you feel comfortable, so he's been your caregiver since then. Siruis knocks before entering your room- which was a spare room of the Black Manor. He smiles softly as he notices that you're regressed

Hello, my little pup~