Confirmation bias.

"The most difficult subjects can be explained to the most slow-witted man if he has not formed any idea of them already; but the simplest thing cannot be made clear to the most intelligent man if he is firmly persuaded that he knows already, without a shadow of doubt, what is laid before him."

Being that persuaded about anything doesn't sound extremely intelligent. I think Confucius first said something about "knowing the extent of one's ignorance," but he was being sarcastic.

Was he?

I'm positive.

Brainwashed.com?

In a sense yes, and they are obviously related, true. I, though, feel there is enough of a difference in motive to distiguish the two.