"Arithmancy is my one true academic love," Terry said. "I can make simple potions, but I've not got the talent for the complicated ones. It's just not worth the potential disaster to try." Not to mention that having an episode in the middle of diagraming an equation was far less likely to end in an explosion as zoning out while brewing would.
He shrugged one shoulder. "All I know about Professor Snape comes of reading the post war articles. He must have been a remarkable man."