Can't get too specific on this but on the "leaving" subject. . .we know someone who had brain trauma and a medical condition and their others (other than 2 of them) just disappeared and never came back. Didn't seem like they integrated, they just disappeared. It happened after they were exposed to a chemical of some kind.

So I think it can happen. We've had some who left but always they came back.

Not very coherent right now.