Studying

 Perhaps cheating on a test was not the smartest use of a genuine magical spellbook, but if Richard was a smart guy, he wouldn't have needed to cheat in the first place.

So, it was hardly surprising when he botched the simple mind-reading spell. Instead of plucking the answers he wanted from his professor's brain, he wound up inhabiting her lovely body. In a panic, he used a spell to teleport home. Unfortunately, his clothes didn't quite make the trip, but at least all his parts were still attached.

After that, Richard was too distracted getting to know his sexy new form to give much thought to arcane matters. It wasn't until much, much later that figured out how to correct his mistake, and by then he wasn't at all sure he even wanted to go back to his old body.