Hey, sorry you're struggling with this. I do too. I'd also never heard of it... here's what I understand.
I view "dissociation" as a bit of an umbrella term.
The memory loss stuff is called "dissociative amnesia" and is pretty common in trauma. In fact one of the symptoms listed in the DSM is inability to recall key parts of trauma.
I don't remember much of my teenage years, stuff I've said and done, so I just tend to pretend I do around other people. Works for me.
Then there's "dissociating" in general. This can probably be split into three subtypes. Depersonalization - not feeling like you, feeling like the person doing things isn't you, generally not being the person in charge of your body.
The second is derealization - feeling "surreal" or unreal, or like what happened isn't real. Like everything's a movie or a videogame or some whack fever dream, is how I experience that.
The third is dissociation.
I call it "dialing down the awareness." I think it's more of a spectrum - I think about it as like a volume knob on reality.
Dissociation is a protective mechanism in your brain. It's more common for people with developmental trauma, relational trauma or multi-event trauma.
When the source of the trauma can't be escaped, your brain protects itself by escaping it's own way.
I have a mode I call DAF (dissociated as... use your imagination). In this mode, I don't know where I am, what I'm doing, and I don't remember squat. DAF-me is a problem - it wanders off and breaks things, including itself, most recently the bones in my left hand which sucks cos I'm a muso. That's a pretty extreme example of what can happen, but it does happen to some people.
Dissociation is actually visible on EEG as a brain pattern, which is super interesting to me.
There's a few things that help, and there's some great threads on here with lots of grounding tips.
