Random Stuff #023: The dilemma of existence

I exist. You exist. We exist. But how do we exist? What is existence? What does it mean to exist? To me, existence is being self aware. Knowing that you are because you exist.

French existential philosopher René Descartes posits in his famous Discourse On Method that by virtue of our ability to think, we exist because how would you think if you didn’t exist. The phrase cogito ergo sum translates to ‘I think therefore I am’. Our ability to think about our existence, whether in acknowledgment or denial of it, is sufficient proof that we exist. 
So what if we being self aware of existence is just a design flaw in our code? What if all we have been thinking is after all an illusion? What if its an evolutionary trait that aids self aware individuals to survive?