Robert Zemeckis’ best films were box office hits that helped put the American filmmaker’s name on the map like Forrest Gump, the Back to the Future films, and Who Framed Roger Rabbit. With his top box office flick being 1994’s best picture winner Forrest Gump,

Legendary director Robert Zemeckis explains why Here, his new movie starring Tom Hanks, is possibly the most difficult film he's ever made.