…actually means “that is not a me that I necessarily want to project.” Anytime anyone tells you that “that’s not me,” don’t argue with them. The theory is that they have switched to one of their other dialogical selves. Although their logic doesn’t make sense, the fact that they did it is absolutely logical and theoretically possiblel.
It’s not temporary schizophrenia – that is the extreme version of it. It’s just what we might call the switching of selves. So when they say “that’s not me,” that really isn’t the “me” any more. They are a different version of me.
For an explanation of different “me’s,” please check out these other posts.