I'm sure I don't know

Condoleezza Rice on her knowledge of a meeting that she had years ago with CIA director Tenet who, during the meeting, supposedly sternly warned her about Al-Queda attacking America:

"I don’t know that this meeting took place, but what I really don’t know, what I’m quite certain of, is that it was not a meeting in which I was told there was an impending attack and I refused to respond."

I posted this because I found the language she used very amusing. I'm not doing this to single her out for communicative failings (there are better reasons), but just to display some oddities of human speech. We all occasionally say things that are absurd, yet they are mostly valid because people 'know what we mean.'
I just love the phrase "...but what I really don’t know, what I’m quite certain of..."