Every now and again, a fellow _flosser texts me a question I just can't answer—either because I don't know the answer, or because of the medium's draconian character limit. So I'm going to start tossing out these questions to the group.
"Is it ever explained why Marty hangs out with Doc Brown? He's just in Doc's house to start the movie and it's just implied that they're good friends."
— Brett Savage
Back to the Future Co-Creator Bob Gale Explains How Marty and Doc Became Friends (8/16/2011)
Dear Slate: Bob Gale Is Locked in Our Basement (8/18/2011)