This question could be a tricky one and may look confused but it's not so. Why my own existence is confined to "me" and why I did not exist as God or some other being? Why my existence came as my individual soul and not any other soul? Can u get my question? If we're Lords one part of energy, why my existence consciousness was not Lords superior energy? In general, what is existence? Why I am not some other soul? Why my existence was not as deities? Why my existence is as individual Atman and not superior to it? Why am as Jiva? What is basis of existence? "I" here can fall down to lower realms or go to spiritual world. So here "I" is between spiritual and material. So who am I? From this we can understand Jiva we are between spiritual and material. So Atman is a state. So who am I and we? And why we are existing and am existing as me and you and not you and me?
This is a different aspect of the question. It's not who am I, its why am I , the reason behind why am I this and why am not that. Or in nature, aside God, everyone evolved from Jivas?