In a documentary "Student Andriej Tarkovsky" which follows Tarkovsky's notes from his time in WGIK he, among other things, muses on what makes a genius. Genius represents quality without which we can't do, says Tarkovsky. On the other hand if a writer or an artist (his oeuvre that is) is not absolutely necessary he is not a genius.
These ruminations sound weird when uttered by somebody who hasn't done anything yet, particularly when its pretty clear the subject is on his mind most likely because he's set to explore it personally. In another documentary "Rerberg and Tarkowski, the other side of Stalker", Rerberg recalls Tarkowsky intimating he thinks of himself as a genius. It is already after "Andrej Rublow" and "The Mirror", so his reported claim could have some factual support, still such self analysis sounds weird coming from the guy whose philosophical and artistic concerns seemed boldly transcending the pettiness of human nature.
Then in a yet another documentary: "Directedy by Tarkovsky" I found a quote from his book "Sculpting in time". The quote is so powerful that it instantaneously validates self absorption of its author.
Here it is:
"Time cannot vanish without a trace for it is a subjective, spiritual category."
When Tarkovsky in his book talks about time in film it is not that shots and their arrangement represent time - it is that within a shot time is mold-able, it is time within a shot that is the basic building element. And as such is flexible, could be elongated or shortened. Could also, be a subject of other manipulations, found in Tarkovsky's films.