WMD: that's a no-know

As long as we were on the subject of Donald Rumsfeld, here he is "answering" a question:

"Reports that say that something hasn't happened are always interesting to me, because as we know, there are known knowns; there are things we know we know. We also know there are known unknowns; that is to say we know there are some things we do not know.

But there are also unknown unknowns -- the ones we don't know we don't know."

He left out an important category: The things we say we know that we don't know.

Or maybe that's not a category he knows about. Know what I mean?