Not a big deal to me. It's not related to the fields I'm working in, but on the off chance that I need that specific theory I can just teach myself in like a month.
And it's not like we were slacking. Not only is it one of the hardest courses, but we were expected to know a lot of prerequisite material. Prerequisite material that should have been covered in the previous course, but wasn't, because that Professor decided to cover something else for 5 weeks that other Professors teaching the course don't.
The only reason I did 'well' is because I used what little spare time I had teaching myself the prerequisite material.