I wish this was a rare occurrence, but it is not.
The road I travel to work is a 2-lane road running through 2 town centers. It winds its way through woods, small farms (horse mostly), and neighborhoods. The speed limit varies from 25-45, and would be a pleasant drive if it weren't for the idiots that drive it.
Weekday mornings and afternoons, this road carries a good amount of traffic. Especially around school opening and closing times (6 schools on the route). Traffic never moves "fast", you can occasionally hit empty stretches, but mostly share the road with a fair number of others.
This morning, driving through one of the town centers, at the speed limit I let one person pull out in front of me. One. This is always a busy section, and people are always pulling on and off the road. I let one person through. The ever gracious "human" behind me finds this offensive and honks, gesticulates wildly and yells at me. At the second town center, an even busier one, I also let people in front of me. Now, here, the road moves art 10-15 mps, tops. Traffic is always dense, and people are always waiting to pull in. Guess what Mr. Humanity thinks of this? I thought he was going to have a stroke....
Damn people, chill out! Relax, take a deep breath and calm down!