This is, in fact, not true outside of lab, especially if one is a PhysicsMajor.
A student ran into ProfessorPetersen and his wife at the airport. ProfessorPetersen mentioned to his wife that the student had taken physics lab with him twice, as a frosh and currently as a sophomore. To this, his wife remarked, "You had him previously for lab, and returned to have another one with him? Some people would call that masochism."
Personally, I've found that Petersen is one of those profs who will teach you a lot of stuff, but he'll always act disappointed that you don't completely understand all of it. He knows what he's talking about, though, and I'm happy to say that if you learn even a smidgen of what he's trying to say, you'll feel quite smart.