According to co-star Shelley Duvall, the infamous ‘Heeere’s Johnny!’ scene from The Shining where Jack Nicholson breaks the bathroom door took 3 days to film and the use of 60 doors.
At first, the props department built a door that could be easily broken, but Nicholson, who had worked as a volunteer fire marshal, tore it down too easily so the fake door was replaced by a stronger one.
People outside the US may not know that Jack’s line is taken from Ed McMahon’s introduction to The Tonight Show Starring Johnny Carson– even Kubrick wasn’t aware of it! It was improvised by Nicholson and the director nearly used a different take. Carson would later use the movie clip to open his 1980 anniversary show.