My first semester of college I spent the entire time playing golf, goofing off during the middle of the day, partying at night, and spending lots of EXTREMELY HIGH quality time with my girlfriend. Ahhh, that was the life. Amazingly, this didn't seem to be the path to success with my engineering curricula and I ended up with a 0.6 GPA at the end of the first semester. After finally settling down (and switching to another field) I turned it around and ended up graduating with around a 3.3 and later had a 3.9 in my masters studies (not that it matters much at that level.)
My cousin had one good story. His calc professor's method for distributing graded tests was to leave them face-up on a small desk at the front of the room with the numerical grade written in big magic-marker on the front. My cousin came in late to class one time to find that the professor had already returned the tests (he usually did it at the end of class) and saw that his was the only test left on the desk. He went up to collect it and saw a huge '2' written on the front. Since everyone had obviously seen it (and could still see it given the size of the prof's writing) he was mortified. It wasn't even a multiple-choice test. It was partial credit for one tiny little part of a function that he had right.