self can not know everything argument.

 Sorry to say but the brain is not just the senses and memory.

There is no consciousness without brains. At least so far as we can demonstrate.

I have to discount the assumption we would know or feel all of what we are if we are what we think.

I see no reason we would, nor evidence to suggest we should.

Why would I need to feel my ulna and the individual fibres of the muscles around it, or the individual hairs upon my arm?

Consciousness is debated as to precisely what it is, one simplistic view is awareness, self awareness at that and yet that is not quite enough, it can be removed by sleep, by drugs, by being another species, and yet why would species exist as a form in this consciousness if they have none.

For the idea you suggest to be real, the brain would be more of a conduit to access this thing. It would make this thing the god that you seem to allude to, a "mind" if you will that then becomes an "i" and a "you" for what reason is not really explicable, after all if it is so, then it doesn't have a need, it does not need to understand anything because all knowledge would already be present within it and everything that could be perceived as reality and existing would only be what the consciousness could create and imagine and so it would already know all it could create.

Also, people should spontaneously be able to tap into this consciousness, with no prior learning, nothing to explain it, we should be able to connect directly to this mind, and allow our vessel to access the knowledge, of course some may argue that is so and when we arrive at this stage we have achieved enlightenment and re absorbing into the great consciousness is becoming one with everything.

Of course then the end would be the beginning, the consciousness that is formless would have created multiple individualities and realities only to allow it to revert to being a single formless thing.

There is no logic to that, to offer a reason for anything else would necessitate we depend on what we experience, none of us have a way to prove that we should feel all things and know all things if we truly were bodily beings, because no one does feel every part of their body, so you place yourself with an impossible task as the barrier to us being able to discount what you say, however you have not proven that we MUST feel or know these things so i don't see why your concept must be the truth as opposed to seeing reality through that which within this perception we can and do understand things.