Sudden memories causing depersonalization?

I'm new, I'm sorry if this is in the wrong forum. I honestly didn't really know where to put it.

There's a very strange occurrence that happens to me, seemingly at random. I can't pin down any triggers or causes at all. A memory will come to me, very suddenly, and then I'll forget it pretty much instantly. Immediately afterwards, I feel detached from my body. I'm diagnosed with generalized anxiety disorder, and i've felt like this before, but it was always during or after a panic attack. At the moment of these sudden memories, I'm entirely calm and content.

I haven't been through any mental trauma. They're not flashbacks. I can recall the nature of the memories being entirely benign, but I can't recall the content of them at all. I only know that I just remembered something, and then immediately forgot what it was. That doesn't really worry me, it's the feeling of complete confusion and detachment that comes afterwards. I did google it, thinking maybe this was common. What I could find mostly related to memory loss, with no mention of the dissociative feeling I experienced afterwards, and often it would say this was a result of Alzheimer's and dementia that comes with age. But I'm only 17 years old.

I hope I explained myself clearly enough, of course I can clarify anything that might be confusing. Thank you!

Maybe what you are describing is what I've been trying to find out about too Great you describe it that way so I can put another definition to my strange experiences to google further! I have occadionally had hours long tumbling flashes of memory, like when you wake up from a dream and your waking consciousness overtakes really fast and you still see semi transparent dream images/memories but they race away behind you and you can't hold on. Except that feeling keeps coming as an overlay over ordinary reality. I've had it after a review with my boss where I mentioned something personal (anxiety through suppressing feelings?), and went back to work with this going on. And in restaurants with friends or family (again places where I had to behave and suppress my emotions). I have found out luckily that a small amount of Xanax (or perhaps any other relaxant) stops it. I call it "constant déja vu" for wont of a better description. Still have to tell my therapist (a psychiatrist) about it, but quite sure it is a form of dissociation. Glad you know for sure your memories are benign In my case the images are too quick, but also not in themselves scary or nasty. Good luck!