You Know Or Not?

Does anyone of you realise that mostly people start their converstation by saying "You know or not?"

"You know or not? I got this for my birthday present."

"You know or not? My aunt got a new baby girl."

"You know or not? She got married 'cos she ter-pregnant."

"You know or not?" "You know or not?" You know or not?"

How do we know when you did not even tell us before?