essence fragmentation

I've picked up information before in dreams and sleep after inquiring about essence fragmentation a long time ago. I'm not sure if the information I received is accurate, so I'd like to get a confirmation from the group here.

What I learned was that when a soul's essence fragments, it can rejoin because the fragments remember that they were once apart of the same whole. The fragmented essence's individual memories of who it is create resonance amongst the fragments that tell each other that they are one. However, there are some cases where the essence has become so fragmented that it permanently loses memory of itself and cannot remember who it was. As a result, you would not be able to find those essences since there is no resonance between you and those fragmented aspects. In those cases, the essence may never rejoin with its original whole.

Does this sound right?

If you are talking about Soul Retrieval, I would imagine that it is possible there could be added complications and difficulties and things that just make it harder than usual - but not impossible.

from what i've been reading lately, it seems that the soul fragments, which retreated during trauma, often go to a place that is far more "friendly" than real-life has been.
often the shaman doing the retrieval finds that the soul fragment refuses to come back, and so has to be persuaded, and even tricked, into coming back.
even when it has returned, it needs to be nurtured by the individual it was once a part of. retaining the memory of the original trauma, it may be unsure of it's safety, back in the real world.