By birth, the sub cortical part of the brain knows everything necessary to
keep the body alive, and with fully functioning humans,
by discovery, imitation, and instruction, the conscious part knows things which
make life more livable (technical, practical thoughts);
the cortex also houses neural activity whose only reason for being there,
(from any pragmatic perspective)  --   is that  --   something must.
 

The brain’s activities extrinsic consciousness are of no pertinence in the certain man’s realization of what is really going on; only the latter two, supra described,
bear on his interest, and even then, ‘tis not the contents of the two,
but the fact that even though they are clearly of two entirely different orders,
men’s minds constantly commingle the two, the result being that
in their brain’s non technical,  recreational & speculative activities,
it presents to men inner pictures of life that are partly facts and partly dreams;
the thought area of the brain, when by reason of circumstances is not forcibly engaged in survival relevant activity, continually mixes together things which
it actually knows-about the physical universe,
and things which exist only in its private realm  --   things it merely thinks-about:
not things it in any way actually knows-about --
for they are things that there is nothing to “know about” –
they be things the mind created, so anything it says it knows about these things
are simply additional things it made up about the first thing it made up.
 

Any brain in any reasonably good condition if momentarily presented this fact, would, momentarily be unable to deny its truth,
yet the standard programming of our species’ brain is such that
the awareness of reality just described, is also so fleeting and non rememberable that, for all practical purposes --  it never happens in the life of an ordinary man;
his perfectly normal thinking runs a lifetime incessantly mixing, then confusing
things that he and his brain actually know  --
which are always about something he can touch  --
and things he and his brain merely think-about,
and without he have reason-to and the ability-to make and hold this distinction,

As is the common case from the view of the certain man,
it is not a matter of one of the two types of things that the brain can entertain
being the right thing and the other the wrong;
to be a complete human being, both must be native to your mind;
their qualities could not be more different in a four dimensional reality,
but the condemnation, or imagined extermination of either is foolish;
what the man who would see needs is a clear  and constant
separation in his mind of the nature of the two  --   that’s all –
damn near impossible to execute  --   but realizing the validity of this,
and being consistently mindful thereof will radically alter your internal landscape,
and make more feasible your approach to that heretofore untapped spot in your cortex that can see through everything;
forget about Superman seeing through walls and mountains and concrete –
this part of a certain man’s brain sees through everything.
 
 

Simply, calmly make note in your own head that in the never ending
torrent of thoughts magically appearing and flowing through your mind
are things that you and your brain unquestionably know  --
and make once-&-for-all note that everything you know for an indisputable fact
is always about something that has a physical reality  --
and then a whole bunch of stuff which --  without it be subject to specific thought  --  you and your brain act like you know, but which you clearly do not:
it is just stuff & things that you think-about.
Hardly any one ever born to this planet and our species has the innate wherewithal to realize this (not to mention the glaring lack of need to),
but for a certain man who shows up now and then,
doing so changes everything  --   for him  --   in him.