Here are few quotes regarding Knowing or not Knowing, for that matter, the Unknowns:
If you don’t know what you want, you won’t know when you’ve gotten it.
What You Don’t Know Can Hurt You.
You Don’t Know What You Don’t Know Until You Take the Next Step.
What you don’t know is often far more relevant than what you do know!
You don’t know what you do until you know what you don’t do.
It Pays To Know What You Don’t Know.
And finally the best of the lot – known unknown:
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.