I just don't know how accessible the memories of past lives are. In all of the past lives I ran in session or recalled out of session, perhaps I can count on one hand the ones that have the ring of truth. The rest was wishful thinking or dub in.
In a way it is like Hubbard's theory on charge as discussed in the Time Track HCOBs. It comes to life when you put your attention on it. When I look at past posts I have written here, many times I have no recall whatsoever of having written them, and less of the circumstances surrounding them. If I tease at them, I can I can figure out my frame of mind, or recall posting them. I think past lives are a lot like that. They cease being created, and it takes a pretty specific trigger to resurrect them.
I guess it is like your past lives are kept in a vast unlit room, and it is pitch black inside this room except for a small lighted area which are your current memories. When you look further into your past, all you have is a small flashlight, and see a miniscule portion of what is there. Occasionally you hit on something real, the rest is conjecture.
For those that aren't familiar with Hubbard's Time Track HCOBs which were on the old Dianetic courses such as the HDA and the HSDC, he discusses the permanently charged portions of the bank (GPMs) and the ones that charge up when you look at them - locks - which sit on earlier charged incidents - secondaries and engrams. If you believe in locks, secondaries, engrams and GPMs having sway over a person's actions as Hubbard puts it, it make sense. Otherwise, not so much. There is a really interesting description of the auditor's role in controlling the time track, much as a projectionist running a film forwards and backwards, because it really sounds more like a description of a hypnotist at work than anything else.
I have a friend who thought ( and may still do so) that his son was someone he knew that was on OT3 but passed away. So, you aren't the only one. Who knows?