I’ve seen this in action so many times and never knew there was an official name for it.  It’s nice to have some backing to the saying “The more you know, the more you realize what you don’t know.”

Now I need to find strategies to combat this? Any suggestions? Other than something along the lines of “You are totally clueless!” (Which probably wouldn’t go over very well!)

The Dunning-Kruger effect is an example of cognitive bias in which "…people reach erroneous conclusions and make unfortunate choices … their incompetence robs them of the metacognitive ability to realize it"[1]. They therefore suffer an illusory superiority, rating their own ability as above average. This leads to a perverse result where people with less competence will rate their ability more highly than people with relatively more competence.

Dunning-Kruger effect – Wikipedia, the free encyclopedia