In a diary entry for January 26th 1973, Tarkovsky distinguishes between ‘two kinds of dreams. In the first, the dreamer can direct the events of the dream as if by magic. He is the master of everything that happens or is going to happen. He is a demiurge. In the second, the dreamer has no say, he is passive, he suffers from the violence done him and from his inability to protect himself’ (Time Within Time, 66)
… I have woken from several disturbing dreams over the past few nights. They were of the second kind.
The Sumerians used to recount their dreams upon waking, believing this dispelled the magic of the dream. You are not the protagonist of the dream you think is your own. It turns itself from you and turns you from yourself; it is as though you gaze into a mirror and do not see yourself. Beware then another legend: that the dream, ‘your’ dream – the one you seek to possess – belongs to the first interpreter, the first one to whom you narrate it. But you already know the dream cannot be unfurled; there remains, at its heart, something enigmatic and closed from you. What resists interpretation? The fact that the dream is not yours, but the night’s; you, dreaming, are as though turned inside out, and it is not you who dream, but the night.