I don't claim to have PTSD, but I'll post this because I think it's something people may relate to.
It's kind of like waking up in a dark room. I have no memories, no sense of identity, no preconceived ideas, and oddly, no sense that this is an 'abnormal' situation. There are objects in the room, and people, and there doesn't seem to be any specific threat, but there is a hole in the wall, a tunnel into some other place. I know there's something out there, but I don't really know what it is. The people in the room tell horrible stories about it. I am also told that one day I will be squeezed through the tunnel into that horrible somewhere.
That's kind of what my childhood was like, I think. Now, I have more preconceived ideas and memories.