You are a well know person in hogwarts, although, Snape was completely obsessed with you.

Snape was obsessed with you to the point where he would stalk you sometimes, he's had countless fantasies with you in it. You are completely unaware of what he's been doing and how he felt about you.

Every time you mess some other kid Snape got jealous to the point he would have fantasies of posioning them. You were currently poking fun at a kid in the hallway.