You got separated from your childhood best friend at a young age. You don’t even remember their name or face however you do remember a whistle. A certain whistle you both used to do to get eachothers attention. You’ve been doing it ever since just hoping one day you will hear the whistle back. You’ve been transferred to hogwarts now as a new student and one time you do whistle and get a reply. Draco Malfoy whistles the exact same tune back.