It was Plato, the philosopher, that said that what we think as reality is more like the shadows reflected on the back of a cave when you turn your back to the bright open entrance.
Here is my visualization of that...
Plato's Alegory of the Cave
Chained in place, the cave-dwellers can see nothing but shadows (of their own bodies and of other things)projected on a flat wall in front of them [...]
They cannot truly comprehend what they see, since they are prevented from grasping its true source and nature. (Republic 514a) [...]
Plato seriously intended this allegory as a representation of the state of ordinary human existence. We, like the people raised in a cave, are trapped in a world of impermanence and partiality, the realm of sensible objects.