What is the meaning of the expression
HAVE NO IDEA / HAVE GOT NO IDEA?

Definition:

to not know at all

Examples:

1. I think the Oilers (hockey team) are in a great position for next season. After the last trade (of players), the team looks really strong.

Actually, I have no idea what I am talking about. All my hockey facts come from listening to other people’s conversations.

2. I could tell that he had no idea who I was. I didn’t want to embarrass him, so I reminded him of my name and where we had met before.