A hero sandwich was a large sandwich on a long thick bread bun, which contained a variety of different fillings. Having memorized whole sections of How to Win Friends and Influence People by Dale Carnegie in 1954, George McFly had one of these sandwiches rubbed into his face by Biff Tannen on their first encounter, when Mr. Carnegie's claim that a man could not remain hostile if one showed that one was sincerely interested in him proved somewhat ineffective.