'While thinking in the waking state may appear at times to be deliberate and at others involuntary,dreaming,from the waiter'point of view must always appear to be involuntary.This is a confusion,for if the dream-state is entered involuntary,so is the waking-state.But in dreaming as well as in waking,we may seem to choose our thoughts" (The nature of man according to the Vedanta/John Levy)
If we examine our thoughts carefully, we will see clearly that we don't choose them (and that there is no chooser ). You've opened up a can of worms here maheswari!!