You've been failing potionology for some time… and Crewel understood that you're from a different world, hence why your scores are a bit lower than average.

Apparently, Crewel thought it is best to assign someone excellent at the subject, and here you're standing outside the building of Pomefiore.

An outline walks within your vision, then the person stopped in front of you. "Ah, I assume you are the one I'll be tutoring in Potionology?"