There is a hint of this theme in the top-level server description page for Sirius (PDF page 86 of the HW_Book in spread format). Users who have chosen to opt out of the “memory game” are called Innocents and there are at least enough of them to be statistically-significant. They aren’t currently elaborated on much, but you’re already on the right track with these questions: one can infer that existence without long-term memory makes them live a sort of Groundhog Day-like existence.
Every user has at least enough embedded processing and temporary recall ability (call it RAM if you like) to consciously observe their surroundings and follow through on short-term decisions and goals. I’m sure many, if not most, Innocents have at least a couple of fond recollections they haven’t gotten rid of or overwritten, they just aren’t actively pursuing more or maintaining a coherent self-aware timeline outside of the immediate present. For some users this is enough, although for obvious reasons they might have trouble explaining their justification if you asked how they arrived that decision for themselves! Obviously, ownership of Memory storage allows for the development of a more complicated and self-aware long-term identity, and the majority of users described in the book are looking to acquire memories or at least hold onto the ones that they have and maintain a continuity of self-aware existence.
Anyway, the concept of the Innocents is not yet fully developed, at least in part because their motivations don’t obviously make for either great PCs or easily- understood antagonists, but I’m interested to hear how you choose to integrate them into your personal take on the setting. They will get more fully-fleshed out at some point.