Now to prove something isn’t absolutely true, it needs to change completely. For example if a screen showed only blue color all the time, you would think the screen is blue in essence. But now if the screen changes to red without even a trace of blue, what would you conclude about the nature of the screen? You would conclude that the screen is neither blue nor red and its nature is something other than blue or red. Now imagine this screen starts flashing 1000’s of colors each totally distinct from the other. What would you now conclude about the nature of the screen? That it is beyond all the colors that were seen, right?
Something similar applies to altered states. For example if you experience the world as filled with dead inanimate objects, and in your entire life everyone you met validated this model, and if you have never seen the world as anything other than this model, then you would believe that its the truth or fact. But if you have experience a range of altered states, by subtraction, you know that none of them are absolutely true.
The same holds true for your identity too. Seeing all the sides of yourself is like seeing completely different colors on the same screen. What does this speak about the nature of the screen or your identity? Wouldn’t it indicate that your essence is beyond all that was perceived?