I stand by thinking that the problem with memories fading is that (experiential) memories mostly work by replaying a frame of mind and checking the result for i

I stand by thinking that the problem with memories fading is that (experiential) memories mostly work by replaying a frame of mind and checking the result for internal consistency, and if your frame of mind deviates too much from when the memory was formed, this fails; so memories you retain are memories you rehearse and thereby iteratively bring forward in a similar manner to if you walked a large software project that has had incremental "upgrade" steps from 1.0 to 1.1 all the way up to 39.75 or something. (This would also help underscore why being in the same "place" or "frame of mind" for memories makes your recall scores better - or the stories about people who take mind-altering substances and have memories that they don't recall when sober but can recall reliably the next time they take said substance.) So killing neurogenesis might preclude this problem by preventing your mind from changing enough to make this failure mode happen. (This would also explain why we freak out when other kinds of "memory loss" happen, e.g. from dementia or old age - it's not that we found it but it doesn't import, it's that we literally can't find it, and we don't have great handling for actual memory loss, so we freak the hell out. This could also be the reverse, where we load something and don't notice the consistency checks failing, and then as those are pointed out we become increasingly distressed at the cognitive dissonance from different parts disagreeing on the sanity of what we said, but...)