I have thought quite a long time about whether to post this or not @wwf. However, seeing as honesty and transparency are some of your stated principles, I'd like to be brave and respectfully share a couple of my thoughts about your post.
For me it is now axiomatic that all manifestations of dis-ease in the body have a corresponding emotional element which has not been processed. This wants release; and it may have to start yelling louder - ultimately manifesting as something physical, in order to get attention. The correspondence between the emotional and physical can be quite literal - for example knee issues corresponding to pride (unbending!).
You have "been through chapters so dark that I would not wish it upon my worst enemies". This allows for the possibilty (IMHO) that there might be some sub-conscious incentive to supress painful stuff which may yet lie beneath the deepest layer of healing undertaken. Could this be a 'forgetting' that is having an external manifestation as 'not remembering'?
This is an offering to you in case it may strike you as valid and you haven't considered it already. If I am way off, I apologise - it comes from a place of good intentions, and I warmly wish you all the very best.
Namaste
RE: In the interests of full disclosure ...