Drivers who can't accept that they are in the wrong.
Classic example of this today - coming over the roundabout and signalling that I'm taking the next exit, must have been no more than 5m from leaving and a car just jumps in from the road joining on the left so I have to slam my brakes on to avoid a crash. So, given that this idiot has caused an issue, and to make them aware that I do actually exist, I give them a parp of the horn.
Now any sane individual in this situation would put their hand up or otherwise use some mechanism to indicate contrition - "yes I know I was wrong - sorry". But no this driver thinks the correct response is to wind their window down and flick me the V sign as if
I'm somehow the one in the wrong.
I accept that sometimes people just make mistakes whilst driving, and even that some people are just intentionally gooseberry fool at it. But own your strawberry floating mistakes and apologies you utter twonks!