Let's be honest for a second : I don't think that I understood what the movie was about. I had a fragile grasp of most of the scenes, but adding them up doesn't make much sense to me. I did enjoy the poetry and the contemplative scenes though. I absolutely have to watch it again.
Tarkovsky belongs in the pantheon of European art cinema that influenced Woody Allen. The blatant narcissism in this film is explicit in many of Allen's films. But unlike Allen who is a comedian, Tarkovsky had no interest in helping the audience follow the story.