Saying that goes something like this but I don't remember exactly "There are some things that you know that

Question

There are some things that you know, that you know. There are some things that you do not know that you know, there are some things that you do not know that you do not know.

Can anyone tell me who said it and the correct quote?

Answer 1

There are known knowns. These are things we know that we know. There are known unknowns. That is to say, there are things that we know we don't know. But there are also unknown unknowns. There are things we don't know we don't know.

Donald Rumsfeld