I rented out and have been watching the "special edition" video of
Planet of the Apes (released 1968, screenplay by Michael Wilson and Rod Serling, based on the novel by Pierre Boulle) with my 12½ y/o daughter. She had asked me to recommend some good SF to watch, as she is studying the category of Science Fiction in her English class. (I also rented out THX1138.)
This was the first time I had watched POTA on a video - I had previously only seen it in movie theatres and TV reruns. As we watched, there was one point in the film where the three orang-utan judges cannot reconcile themselves to the remorseless logic of the unwanted proposition that the human - Taylor (actor Charlton Heston) - must have evolved on their own planet,
if he had
not come from space as he insisted he had done (and which latter was a proposition they absolutely rejected as being absurd).
I thought to myself "What the heck are they doing with their hands?" - they were balling up their hands and fumblingly putting them to their faces - whereupon at 1:11:50 my daughter suddenly exclaimed "Oh! It's the three monkeys!".
I do not recall ever having observed this deliberate little joke when I watched the film previously. Very droll. I see it's mentioned in IMDb.
Favorite Sci-fi movies?