Who is the Original?
We have always been plural. We never integrated as a young child, and there was no first dominant consciousness. There is no such thing as the person we were meant to be.
However, there were two of us, each in one hemisphere of the brain, who reached self awareness at roughly the same time, Jenifer and Eh. And nearly everyone else has split off from or been created by them, or by one of their children. Phage being a notable exception.
We consider Jenifer and Eh to be twins, born with our body.