I have always liked 2001 A Space Odyssey.  It has been my favorite for ever.  And now to see so many references to it - even the Barbie Movie starts with a homage to 2001.

Standing on the Shoulders of Kubrick: The Legacy of "2001: A Space Odyssey" Mini Documentary

Recently I've discovered the hidden language of the film.  Kubrick's masterful use of a visual under current story, quite different than the verbal story.  If you believe someone can and did have such a masterful plot to tell two stories, one inside juxtaposed to the other.

Is there a double entendre throughout the whole of the movie?

I'm going to rewatch the movie with this new awareness - going to see for myself.

Contray to most movies, the book did NOT predate the movie.  Kubrick conceived the script and was filming as Clark was writing the novel.  And there may have been a bit of subterfuge ongoing.

The hidden depths of 2001: A Space Odyssey - film analysis

Now some people believe that NASA hired Kubrick to film and produce the Apollo Moon landing.  And even Neil deGrasse Tyson has an opinion - spolier - it was filmed on location.