I believe it is a form of dissociating. I've been workng on this and trying to notice when it happens. I think that sometimes my confusion is the first step toward dissociating (which I used to call "checking out"). If it gets caught before I really space out, like if someone calls me on it just as its happening, then its confusion because I'm still here, but not here and trying like hell to be cognitively aware of the conversation but unable to pull myself back in time. I'm somewher between here and there, wherever there is!