Stanley Kubrick is what many would consider a mad genius. He was infamous for shooting an insane number of takes for each scene, sometimes 50, 60, or more for reasons that weren’t totally clear to the actors.
For example, Harvey Keitel was originally in Kubrick’s final film, ‘Eyes Wide Shut.’ After shooting a scene dozens of times and not receiving feedback as to what Kubrick might want done differently, Keitel essentially said “to hell with this” and walked away … from a Kubrick film!
Also, the ending to ‘2001’ has always been a topic of much debate. There’s actually a recorded phone interview with a reporter in which Kubrick specifically explains the ending. Lo and behold, it’s actually OUR video, and it’s embedded below.