I have to deal with them in my business. They are extremely self centered and unbelievably stupid.
It's not that they are just stupid, as if that is not enough, but they are ferociously anti-knowledge if you ask them the wrong question. Cars, movies, music, Zen Buddhism they know everything. But if you ask them anything about history be ready to get pummeled.
When was the Civil War? I don't know that shit dude! Get the hell away from me!
BTW, I have seen this attitude even with software engineers with a master degree. They know everything in the world about software and computers but absolutely nothing else.
Somehow they have been trained to believe that the general knowledge all of us learned in school is stupid for some reason. And people know general knowledge are stupid for knowing it. I don't know if they really believe that, or if it is a defense posture for being deliberately stupid. Either way, the effect is the same.
General knowledge is going the way of the dodo bird. Today people are being taught to be functional drones with a specific task. But no broad knowledge at all. It's a brave new world we are living in today.