2001 Is a Black Comedy and It Fooled You Because Acid

 Clue 1: It's a Kubrick film and it has the military in it. 

Clue 2: There's an interminable intermission featuring a blank cinema screen. 

Clue 3: The monolith is a blank cinema screen on its side. 

Clue 4: Dave's reaction shots in the Stargate are almost identical to Scotty freaking about women in Vertigo. 

Clue 4a: There's a sperm and an egg in that sequence. 

Clue 5: Everyone ends up in a gigantic version of the bone, which tries to kill them for being inefficient. 

Clue 6: Hyperspace is Versailles. 

Clue 7: Acid heads get upset when you say this. 

Clue 8: The climax of human evolution is a gigantic baby. 

Clue 9: The thing that kills a warthog turns directly into a waltzing space shuttle. 

There are many other clues.