Although I suspect proto-consciousness is the answer, I realize I'm not presenting any evidence for it. But I'm enjoying trying to develop a hypothesis that, at least, isn't self-contradictory. Maybe someone will figure out how to prove or disprove it.
I suspect there will be changes to how this sub-forum is arranged. I'm writing it all down as I think of it, so it's far from polished. At least as of August 1, 2024.