Partly due to being in Russian and partly due to its legendary slow pacing, Solaris (the 1972 version) is notoriously hard to follow. Often called the Russian 2001, Solaris takes place on a space station where the researchers are starting to hallucinate and go insane. The hallucinations cause plenty of questioning about the nature of their reality, which when combined with a psychologist main character and the question of how to approach a truly, truly alien lifeform has lead to many scratching their heads. The final open end to the film leaves just as many questions raised as it answers. It’s still a damn good movie if you can handle the glacial pace, but don’t expect any easy answers.