He had been to Camelot in ye olden King Arthur times but he hadn't been one to hang around at the library. Crowley had been out there in the field fermenting... things... in the damp English fog. He had no reason to doubt Aziraphale's words that the librarian back in those times had indeed been fierce. She or he might even have been of the round table for all he knew.

"Of course my magic is up to snuff!"

Affronted by the idea that it would not have been, and for the moment blissfully unaware that he had been gifted a new set of unfamiliar skills, he could be as boastful as he liked.

"I'm obviously going to be top of the class. I doubt anyone else here has been using magic as much as you or I."