derealization? or switch?

Does anyone ever look at someone close to them, like mother or husband and get a feeling like you don't know them?

It's not even like that..intellectually, I know I know them, but I am looking at them puzzled. They seem unfamiliar to me and I begin to examin them.

Is this Derealization? or is this some alter who is just not out much experiencing them for the first time in a long time.

Family, friends, coworkers, myself. Get it all the time. It's derealization/depersonalization.