Dissociation is common for people who experience trauma, whether as adults or children. It is a normal response to unbearable stress.

I've read about deer or antelope or some kind of prey animal that will dissociate when they are attacked by a predator. If they survive the assault, they will literally shake it off and resume normal behavior. I think that was in the book Waking the Tiger by Peter Levine, but I'm not sure. Anyway, his theory is that animals and humans both dissociate under extreme stress, but that humans sometimes cannot "shake it off" and then store the trauma in our bodies. And that causes things like DID and PTSD and BPD.

Probably more information than you wanted-but yes, dissociation when under attack is very common.