[Shootohoist]

I think what you are asking is an interesting question. Why a sense of self naturally prevails in the mind and how that kicks back in even if you have lost your memory completely. I think this is what we call "nature". That is the way things naturally are. If you observe an infant you can see that it has a basic instinct for survival. Even a plant responds to sunshine, turns it branches in the direction of the sun. It has a survival instinct of its own and a sense of self-protection. That's just the way things are in nature imo.

The Madhyamaka call this the innate self-grasping mind.