Around 6 years ago, I finally watched all of the special features on my Back to the Future DVD boxset. The next morning, as I was gushing to a co-worker about all the behind the scenes trivia I had learned she patiently nodded before laughing and politely asking, “How did you not already know that Eric Stoltz was the original Marty McFly? Even I knew that. I thought you were supposed to be the real film nerd, not me.” Ouch.
It was, as the AV Club recently put it, a kind of pop culture facepalm moment, i.e., when I realized I had taken too long to discover something which everyone already knew. The story goes that Michael J. Fox, the original choice to play Marty McFly, couldn’t get out of his Family Ties commitments to be in Back to the Future. So, Eric Stoltz was cast as Marty, but around halfway into filming the higher-ups (i.e., Spielberg, Bob Gale, Robert Zemeckis) decided he wasn’t cutting it, bringing entirely the wrong energy to the role. He was cut loose. A deal was worked out with Fox where he would film Family Ties during the day and Back to the Future at night and on the weekends, and the world was the better for it (despite Fox’s understandably chronic exhaustion while filming).
For Back to the Future fanatics, actually seeing some of that original Eric Stoltz footage has been their holy grail, especially since it turned out Zemeckis had filmed far more of the movie with him than we’d previously realized. However, YouTube user Too Old to Grow Up just made a convincing argument that some of the Eric Stoltz footage actually made it into the finished film; we just never noticed it before.