I've not had anything happen as bad as all of you but there was some CSA from an older "friend" and i have 2 vague memories of it happening but not the details except for the last time it happened. I never remembered it/thought about it until i saw this person 23 years later and got an instant flashback.

It def happened several times not just the two instances but those two times are all i remembered and even then not exactly why it happened, how it came about, what exactly that person did to me. I don't remember how i felt about it at the time, i don't know why i let it happen. So much i don't know.

So yes it's very possible not to remember.