We sense an incredible amount of data, far beyond what gets filtered down to a tiny articulable amount. Sometimes some of that data bypasses some of those filters, or seeps thru anyway, and reaches conscious cognition anyway – kinda freaking us out in the process with the manifestation of the perception & interpretation. AFAIK the phenomenon of autism is the lack of certain mental filters, inundating the autistic’s cognition with huge amounts of raw data, allowing for the “savant” ability to perceive & recall intricate details, and as a consequence be unable to focus on particular details which are socially expected by “neurotypicals”.
For a more sane analysis of nuanced perception, read Tom Brown’s “Science and Art of Tracking”. Might help translate the weirdness of perceptive dreams and nutcase supernaturalism into the reality of better understanding what you do perceive.