I got a 37% on the mid-term and thought "holy f, this is a class I am not going to pass, wtf is going on?"

I went to the prof during office hours, explained I'm confused, he asked to see my mid-term and exclaimed "Hey, you got the highest score!"

To this day I can still see the gray skinny little textbook with the title "Denotational Semantics" and I still wonder "what the heck was that course about?"