Things to use as perspective on the inadequacy of the human apparatus (ie physical senses, experience) to perceive all of reality (ie that which exists regardless of our awareness or comprehension of it)
1. The human eye: can only perceive certain wavelengths of light. Anything reflecting only frequencies the human eye cannot perceive would be 'unseeable' without augmentation
2. Carbon based life form, the brain, apparatus for consciousness, the allowance of other (non carbon based) life forms that contain (non brain analog) apparatus for consciousness in physical beings that would remain non translatable to our own consciousness by nature of material difference
3. The inability of two consciousnesses to be the same