8. The Commentator
I'm guilty of this. A lot of cinephiles are. We're chock-full of informative nuggets that you couldn't really care about if your life depended on it. The Commentator is that person who fills in all the lines outside of the story world. They're the person telling the stories of how Brad Pitt got cast instead of Johnny Depp, and how Depp turned down the role after Gore Verbinski stepped down from the directorial position. Odds are, the person you're commentating for is probably just trying to keep up with the movie, but you keep stepping in with your brilliant asides and tidbits. "Do you know what TV show those two were in together?" "...n-no..." "
Deadwood. He played Sal, and he played Dan--" "Hey, can you die real quick?" Just wait until the movie is over and respectfully point your friend in the direction of the IMdB trivia page if you really feel they'll get a kick out of what you've wasted your brain cells remembering.