Note: this chart not to scale; the red slice is unimaginably large.
Although it merits a spot in the update at the bottom of the post, I would argue that one subcategory of the Shit you don’t know you don’t know is really more dangerous, and important, than the rest – the Shit you think you know, but don’t. This results in active stupid, truly dangerous or offensive behavior. Someone who doesn’t know something, when exposed to knowledge of it, will usually accept that there is something to learn. But if you’re convinced that you know something you will have absolutely no motivation to learn it, no matter how desperately important it is that you do.
I also dig this characterization of Don Rumsfeld’s comments from a few years back:
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.
—Feb. 12, 2002, Department of Defense news briefing