Trying to maintain attention while sleepy and reading or listening to music it is easy nod for a moment and fall into a very brief dream. These events of other consciousness are not really dreams but fragments of dreams, or pre-dreams, as if you have plunged into the midst of a story taking place in another scene and have not had time to orient yourself. It's not even clear if you were just there in that scene, or it was only the scene, because it is almost impossible to remember anything of it when you jerk back into your drowsy mind in the present, only that it was quite vivid, seemed quite natural, and had nothing to do with anything you can think of. If emerging from it seems a jump-cut, moving into it must have been seamless, since you can never catch the moment when the other scene takes over. At best you can catch yourself just before falling into it, on which you'll give you head a little shake and feel the effort of coming awake again. It is as if the blocking in of the situation is entirely effortless, and the first thing that happens is that the situation comes into focus, a situation consisting of a setting and some other characters already engaged in various activities. Presumable it is only after a further interval, which might be permitted to develop later when you are lying in bed but not now, that what we normally call a dream can crystallise out of these preliminaries, and when this happens your role thickens and takes on the motives and purposes of a character fitted with a self into which a familiar coordination of thoughts, feelings, memory and of distinctions such as of self and other, inside and out, earlier and later, can be located, which is your self. Only in the this later phase can it become a dream. What this shows is how much more goes into having a self, it is like the meaty flavour in a soup that comes from adding a few bones, without which you would have just had a thin, evocative but unsatisfying vegetable infusion.