When waking from deep dreamless sleep, for a second you have no sense of identity at all. Then you start to feel a "selfness" again—but are unsure of where you are—and then finally the immediacy of the sense-world hits you. There is no clear evolutionary reason for sleep in general (save hibernation), and certainly none for deep sleep particularly, which, if you think about it, would seem to be maladaptive; in the seconds it takes for you to be roused and reorient yourself, you could be attacked or eaten!
So, if there is no clear scientific reason for sleep (or at least no convincing reason presently), then applying the problem-solving principle of Occam's razor, it would seem most likely that deep sleep does not have a biologically-selected function at all. So then... Could it be that the mind, for non-biological reasons, simply needs to regularly touch the identity-less absolute of pure non-dual being? Maybe the waking self-identifying state—full of illusions and delusions—cannot be sustained without routinely connecting to the unconditional source (whether one appreciates its importance or not in the waking state)? Perhaps without this regular stabilization in simple being and "beingness," the entire contraption we call ourselves just loses its spark and peters out. Maybe without this grounding, we get lost in the absurdity of our waking existence, eventually becoming adrift to the point of insanity, like Bowie's Major Tom floating in his lost spaceship.
From our "normal" perspective, conditioned by the cause-effect world of us-or-others, deep sleep seems the strangest of all possible states, completely counter to what seems reasonable for humans to do in a "real" world. Think about that! In a sense, this argues that deep sleep may be the most fundamental state of all, since it occurs despite that by everyday logical reasoning it shouldn't. If it is so far out there, and yet we still need it consistently, then it stands to reason that it must be super-important in a way that we cannot grasp.
Deep sleep may be our continuing connection to the real reality of simply being—or simple beingness.
— Gabriel Fenteany, March 20, 2016
