there's a world out there. we know it through our memories of it, which in our minds construct a "world mapping" through which we remember our world and its natural laws, as best we know them, and use those to predict it. it is through memory and prediction that we know our world for the most part, with observation of a tiny fragment of it at any given time providing our immediate stimulus, because it is so vast. this is a brilliant design feature that allows me to know that new york exists, that continents and weather patterns exist, without having to observe them - in fact, i can be in a windowless room and still know that weather occurs.
the consequence of this system however is that we must remember what we seek and then not overlook it in our daily filter. think about this: if you were to attend to every detail you actually see physically, the processing time required to even move through a room would be crippling. instead, you see patterns, match them to memories, and thus tokenize objects: there was a car in the garage next to the drive-thru. this perceptual process is how memory, language and logical analysis work.
some people, usually in academia, will tell you this is all bad; i'll simply repeat what i say elsewhere, which is that with eternal values in mind, one can approach almost any method and make it serve a better goal.
separating the wheat from the chaff is a mechanical process, as is perceptual filtering, but it like most things in life is work: summoning the energy to sort wheat and chaff. how does one do this in a meaningful way? if one's values are bad, the definitions of wheat and chaff become absolute, and one only sees objects that are 100% wheat or 100% chaff; this is a procedural error in that one is organizing all of life around a single process, such as the discernment of good and evil.
we must continue our harvest process, but understand it in context.