First off, I really like this poll; I think it's a good discussion to have. I wound up answering "something else" though because my gut tells me that none of the 3 options is really the heart of the problem.
To me, this SAMD thing sounds equivalent to the sort of bad memory you're discussing so while it's pretty good as a more precise description, I don't think it really explains the problem. The other two options definitely seem to get closer to a cause, but I feel like (in my own life at least) dissociation and lack of connection are mutually reinforcing; the real problem is whatever keeps that cycle going. I'm honestly not sure what that is, although it's a philosophical problem I'm working on right now.
I definitely relate to what a lot of the posters are describing though. In terms of remembering objective details like "A happened before B," facts, or little, salient details, I have an unnervingly good memory. In terms of emotional recall about my own life (and the vibrancy of my memories) though, it's been rusty for a while now, and I've especially slipped in the past year or so.
I don't really have too much more to add, at least right now (fingers-crossed, I'll find at least a working hypothesis in the coming months). I do want to give everyone a little encouragement though because I don't think these memory problems are necessarily a permanent, inherent thing. I've brought it up on the forum once or twice before, but in the few occasions when I've felt the dissociation and numbness lift, even memories of times from when I was in a deep funk suddenly have a strong emotional tone (usually bittersweet). So at least in my experience, the emotional color in memory is reconstructed on the fly just as much as the objective facts.