its not that deep's feed

So after reading the new chapters I'm thinking that Nain was human 500 years ago and he was the one that played that song? And he doesn't remember it bc the rituals are erasing his memories so he forgets about every negative thing so maybe the cicumstances where amon turned him into "shah" were bloody and Nain was wearing the ostrich feather in his hair then? If this is even slightly true then it's crazy that amon knows that he just forgets stuff that is important to him and he expects that Nain will do something that he did in the past. Also the fact that he forgot the painting and everything??? crazy