People who think their smartness and great driving skills should be obvious to someone in that circumstance must have their heads pretty far up their own asses. Chances are a lot of them are also ...
People Who Think It's Their Job To Teach People "Lessons"
I'll put this here as a caveat for anyone who read any of the other bad driver types I mentioned and are motivated to "teach them a lesson" on the road -- and that's not an uncommon attitude. These lesson masters wouldn't dare think of themselves as one of those "road rage" people, and separate themselves from road ragers in their mind because they seem themselves as an above-it-all authority who is using some clever method to "help" other people learn and "make them think," as opposed to being out for petty revenge, like a road rager.
Here's a mild example of that thinking in action:
You know why that person did not seem to notice? Because they were trying to call 911 on their cell phone. "I'M OUT IN THE MIDDLE OF NOWHERE ALONE WITH THIS DRIVER AND HE'S TRYING TO DO SOMETHING TO ME!" By the time they start moving in front of you and behind you and in front of you, you stop guessing harmless little causes like the blinker and start looking to see if they have a hook for a hand.
Or if you can see a lot of rope and duct tape in their car.
At least this only involved passing, though. Some people try more elaborate lessons that could very well lead to an accident, taking them beyond the realm of being a stupid snob and into real jackassery. One example: Some drivers wait until the last minute to merge, bypassing a long and slow line. This annoys me as much as the next person, but some people feel the urge to show that driver how much he has inconvenienced people by tailgating him after, or even during, the merge, and continuing to ride his tail a good long time after, to make sure he notices.
Others like to "teach" a tailgater how dangerous tailgating can be, by suddenly hitting the brakes. If they learn the lesson too well, they could both end up discussing it further on the side of the road while waiting for the tow truck.
Again, a lot of these people like to separate what they're doing from road rage by pretending they're teaching people something, but first of all, they're clearly pissed and lying to themselves, and secondly, both ways indicate a person who is way too high on himself, whether you think you deserve personal revenge, or whether you think you're such an authority that you should judge and teach other people like you are Freeway Jesus.
Either way, you are angling to get shot. If you meet any of these annoying drivers on the road, don't be a goddamned road vigilante, just come here and complain about them on the Internet.
For more from Christina, check out 6 Ways Cities Are Getting Into the Attention-Whore Game and 6 Groups Who Don't Work as Movie Bad Guys Anymore.