The novel for 2001 was written after the movie, as an attempt to explain what the heck the movie was all about. Though based on Arthur C. Clark's short story The Sentinel, the movie itself was actually co-written by both Kubrick and Clark, which goes a long way to explaining why so many people seem to enjoy it so much more while slightly removed from reality. I have only watched it sober, but it is still one of my all time favorite films - proof positive (to me, at least) that the best drugs are taken through the eyes.