The younger generation will not remember that going into a theatre to see a movie, did not always mean seeing the film in order from beginning till end. It might be hard for some to believe that the old timers would often go into a theatre in the middle of the film, see the middle then the end. After intermission see the beginning and then leave at the scene they came in at. Anyone here would like to tell us what films you saw that way? PLANET OF THE APES was one I remember seeing that way.
Back in the old days when anybody could come into a movie in the middle of it. they made PSYCHO on it's initial release an exception where I believe you could only enter at the beginning.