I almost did this in a literature class. I think it was the second day of the class, and we'd read James Joyce's "An Encounter". The prof read aloud sections of a published analysis of the story -- out of some big tome -- and asked us to discuss it. The analysis was so vacuous and absurd that I came inches from simply walking out, which would have been awkward because there were only like 8 students in the class. Mentally, I mapped out my path to the registrar so that I could drop the class and began checking out.

After a bit of classroom discussion, from which I abstained, the professor threw the book in the trash (clang! it was a metal trashcan) and gave a speech about how the analysis was gibberish, and how you can't just make up stuff about what a story says. He then walked us through how you might actually obtain useful insights about what the story means to say. It was apparent he gave that spiel every semester.

I'm glad I stayed; it was a good class.