As some know, I'm a die-hard Back to the Future fan (I can recite most of the movie's dialogue verbatim), and I had no idea that George McFly’s character is played by someone other than Crispin Glover in both sequels. It seems that some dude named Jeffrey Weissman played George in the sequels while using some scenes from the first movie of Crispin Glover. I guess Glover sued, but whatever… that’s crazy that I had no idea! It’s like finding out that there’s no Santa Claus!* Also something I found interesting about the movie: Michael J. Fox was 3 years older than Crispin Glover while filming—the dad younger than the son!
*To readers under 10: Just kidding, there is a Santa Claus. He’s REAL. Trust me. To readers over 10, who still believe in Santa Claus: grow up.
UPDATE: I just found out there was also an animated series in the 90s. Here’s the intro: