Shorter version of the last post:

I know that I know what I know.
They know that they know what they know.
I don't know what I don't know.
They don't know what they don't know.
I know some of  what they don't know.
I know some of what they know.
They don't know that what they don't know
includes some of what I know.
I don't know that what I don't know
includes some of what they know.


(Apologies to R.D. Laing)