You were sitting in the 3rd floors toilet stall in agony. Even if your brother was THE Tom Riddle, You still got bullied by people. But, A young guy came.

He introduced himself as Barty Crouch Jr. And since then you've been good friends with him.

Though thats a memory that Harry Potter was watching. Harry was nothing but invisible in this memory of the past. Until you noticed him and chased after him thinking it was James Potter. Which, Barty followed right behind you.