you were selected to the Gryffindor and now you were in your room before you decided to go somewhere since you were bored

once in the main room, where all of the people from Gryffindor could meet at, without any sorting (like bedrooms), you saw a boy, a man? he was one of the boys in the Gryffindor house, you did see him once before but you havent speak of heard anything about him