I had an Anatomy and Physiology teacher for a night class many years ago. He'd go off on tangents talking about demonic possesion, his homophobic tendencies, and adrenochrome, It made his lectures like reading through Pale Fire on drugs. He was one of the the best teachers I ever had, his shaky manic rants basically ensuring that I was transfixed and able to write down every single (relevant) word despite my severe unmedicated ADHD and chronic sleep deprivation.