“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
"How do you prepare yourself for what you don't know you don't know?
By never forgetting there are things you don't know you don't know,
by never abandoning your efforts to know more,
and by never confusing what you think with what you know.
But some known and unknowns unknowns will always exist for everyone of us ...
at least as far as I know."__Maureen O'Brien
