I didn't misinterpret.

"Dumb people don't know they are dumb" is an idea I think most of us hold (or held before reading this). [insert reference to pg essay/xkcd here]. This article discusses that idea.

The second sentence of the title suggests there is more (or less) to it than we previously thought.

A more accurate title ("All are skill unaware") would be harder to mentally classify. I thought the idea in the blog post was important enough that a small amount of inaccuracy was justified.