> A while after someone (which I can’t trace back) made an interesting (and equally brilliant) observation - there is a fourth option - unknown knowns - that is, things we don’t know we know. In most cases, that person pointed out, the category contains, things we actually know, but prefer to pretend that we don’t.

That's an interesting interpretation, though with a rather negative connotation.

I've also seen it described as unconscious competence, or the highest level of competence -- effortless mastery.

https://en.wikipedia.org/wiki/Four_stages_of_competence