I find people who harp on about the Dunning-Kruger effect quite insufferable. Without fail they appear to consider themselves in the in-group of smart people. Truth is we're all incompetent in some areas and might overestimate ourselves.
@jcbrand What I find mystifying is not the Dunning-Kruger effect, but the fact that people with a high ability at a task underestimate their ability. Like "You seriously think you can't draw? Seriously? You?"