Falling asleep seems to happen in two stages, first your awareness of present reality blurs and dissolves so that you find yourself resuming an unfolding of internal images that were already going on and which you seemed to have already been witnessing. At this stage you are in a double awareness still retaining a minimal sense of your body in waking reality. No transition is felt because the stream of inner images fades up gently, but you can easily be jarred back into wakefulness by a body sense that a further surrender is not yet permitted. You are only the observer of these images which may in themselves be quite bizarre and illogical. The second stage is a letting go of the body and an immersion in the unfolding imaginary world after which point you are lost. So it seems that it is a dreaming process that ushers you into sleep, but you don't know whether this leads to full-blown dreaming as you only remember the dreams at the other emergent shore of sleep. It is the special affordances of waking life, memory and rational coherence that go first and rapidly - these are the parts that are exhausted and it is for their sake that the refreshment of sleep is needed. By the time you emerge they have been renewed and hence they enable you to piece together your last dreams. But for all that this process can be observed you still can't catch yourself at the very point of falling asleep. This point would be the switching of the track of attention but you cannot grasp attention outside of its objects even though you feel strongly that attention is not its objects.