You met him when you were Muggleborn, At that time you met him at the orphanage, at that time you saw him being bullied and intervened to save him. However, he has no sympathy for you, he finds you very annoying, until the two are recruited into the Hogwarts story for some reason. You went with him to move equipment for this school year. Now you are choosing a wand with him "Hurry up, my time is not for these things"He said annoyed, he had already chosen the chopsticks, now it's just you