The science behind why people think they're right when they're so, so wrong

Keep in mind this is about other people, not you.

How is this new? The idea of WYSIATI was well described by Kahneman and others well over a decade ago and seems to cover this.

It also seems to be related to Dunning-Kruger, in that people are very bad at recognizing their own gaps in knowledge.

Hell yeah... I'm completely right when arguing with my wife until I'm not.