Well, I don't really have much experience to speculate with, but my hypothesis goes something like this:
I haven't entirely rejected the possibility that DMT takes you to a higher plane, or another dimension,even a parallel dimension which we cannot perceive, except with our third eye... but I think it's more of a portal into the subconscious, a portal that allows you to sort of view the source code of the computations your brain must make daily to rationalize and make choices based on natural instinct and learned reasoning, but this source code isn't written in english. It isn't really written in any specific medium.
So what if this knowledge is instinctive knowledge, bred through evolution since the first life forms existed, which exists in everything that lives, or alot of things.
I don't know how that would work in to the fact that some plants and animals have no DMT. But I still feel that my theory is probable.
I believe the reason geometric patterns come into play is because of all the mathematical computations that take place constantly while observing the environment, this too is part of the source code.
Another piece of the source code I experienced was the "whispers" Which seemed to be a cloud of thoughts rushing, continually getting thicker, until it became audible, these thoughts were fragmented, as many rushing thoughts seem to be when I daydream sometimes.
What if the subconscious always has visitors, and we can't understand them, so we just ignore them?
Note: I am new to the DMT world, I've only tried it once, My observations may change drastically with any dose.
Death is an awakening. . . One day it will come.
But you'll search the skies with your eyes in frantic wonder.
You will come to realize the lies you've told yourself for so long to survive.
"We fear something that does not exist."
Not only does death not exist, we ourselves do not exist.