it is possible that things are just quiet. in my own experience, that is how i think it has been. years ago, mine were quite active, but i never really had 100% black outs. i used to hear and feel them all the time almost. over the last few years though, it has lessened a lot so that i do not hear or feel them much. when it does not happen for so long then does again, it freaks me out because i am able to think, like you, that i either made it up or i'm in denial. but when i feel them again, it reminds me that they are not gone and are very real. that is what confuses me because if they are not real, how could i feel them like i do? i try not to focus too much on the 'what if' stuff and just deal with things as they happen.

but if you are actively using drugs and/or drinking, etc. that can definitely increase other symptoms including memory loss even in a person without DID or BPD.