As different as they are, your two answers to my question were about the same as the points my guide made in the conversation that followed my experience.
Regarding its importance in guiding someone along in their spiritual development, in my case, it certainly did provide fodder to chew on.
David's point that the "images" don't arrive out of nothing and that they're filtered through the brain is interesting because it suggests to me that what might most be learned is something about the process of the brain rather than about whatever reality might have inspired the "memory." Something like how some dream analysts concentrate on how the dream is told rather than on the dream itself. I don't think that was your point, just an observation on my part.
Thanks for your responses.