There’s a tree outside my window.
Window: Human created object thru which I can use my eyes to see thru.
Eyes: My eyes are parts of my body that are connected to my brain and interpret light.
Tree: I’m told it’s a tree by people that have studied and named such items that dot our planet. I don’t know the people who came up with the word, “tree”, nor do how they came up with the word. I know the tree is there because I “see” it with my eyes. The image of the tree is translated and connected to the part of my brain that uses language to describe the image.

Brain: I’ve been told that I’m part of the human species, and all humans have brains. I have no proof that I have a brain, it’s only circumspect. I imagine that the prospect of my seeing my own brain with my eyes and translating that image with the object that I’m perceiving it with to be something that might only happen in a laboratory of which I’m unlikely to visit. I must rely on what I’ve been told about other people’s research in brains, that I too possess a brain and that it operates in the way that it does, which means that it’s only hearsay. The truth is that there is only other people’s so called brains that allows them to perceive the brain in the way they do, which also means they could be completely wrong by two possible incedences.
1) The brain has a built-in security mechanism that allows itself to not be decompiled and artificially manufactured.
2) The brain has an inability to understand itself.

The result is that the brain alone is insufficient to describe itself, thus, insufficient to describe anything else around it.

Humanity has created an incredibly complex system by which it explains everything around us but is still insufficient in describing anything beyond what the brain can interpret and classify, in which case it is safe to say that nothing is as we describe it because our tools for comprehension are inadequate.