About 2001; It's more of an avant garde' or art house film than a general release that the public will go see. Ifcourse, no one got it back then, most dont these days as well.
Apes in Africa go bananas. A black thing lands infront of a group of apes, an ape uses a bone to kill another ape; we jump-cut millions of years into the future and see ships in space. Humans end up finding the black thing on the Moon, and decide to send a ship to Jupiter. Follow me thus far?
A talking computer decides to kill all astronauts, a survivor shuts off the computer, leaves the ship, and is taken on a space journey, and ends up in a white room.
In that room the astronaut gets old, eats, lies on a bed, the black thing pops up infront of him, and he dies... and poof, a baby appears, and then he floats in space above planet Earth.
Got it? If you did, you deserve a Ph.D.