Imagine your knowingness as an information stream of images (memories included), smell, feelings, sound etc.
For most people the information stream has the ego dominating.
When the ego is strong people identify themselves with the idea of them based on their memories, beliefs, culture etc.
When the ego goes away I think you are left with who you really are which when you experience feels eternal and permanent and is a placeholder in which everything appears.
Maybe it likes all the drama and want it to forget who really it is? Like how we play games or watch movies?
Or maybe the forgetfulness is a side effect of creation and not intended.
Maybe it has no intent.
I am not sure. I can only guess as an ego by referring to things I saw in the past.