"Ignorance more frequently begets confidence than does knowledge" - Charles Darwin
Yep, we all know that person, in my case that crowd...I need to go back and add that tag to a hundred articles...
The Dunning–Kruger effect is a cognitive bias in which relatively unskilled persons suffer illusory superiority, mistakenly assessing their ability to be much higher than it really is.
Hmmm. I'd completely forgotten about this. The problem is that we all have our blindspots, and I sure as hell have mine...but, as the effect notes, I'm probably not able to see it...
Dunning and Kruger attributed this bias to a metacognitive inability of the unskilled to recognize their own ineptitude and evaluate their own ability accurately.
But my favorite has to be:
...The study was inspired by the case of McArthur Wheeler, a man who robbed two banks after covering his face with lemon juice in the mistaken belief that, because lemon juice is usable as invisible ink, it would prevent his face from being recorded on surveillance cameras....
Read more at the Wiki, and the next time you're speaking with that co-worker you might want to work in the term...
Note: In the event that you've seen me work a magic trick or a hot woman at a bar, I'm aware, I'm aware...It's only 9 parts incompetence, the other 1 part is entirely Irony...
Read through to the "See Also". Oh, yeah...