Apart from the general amateurishness of many cyclists (and the roads are no safe place for squishy amateurs) there are two things they refuse to accept, despite how obvious they should be:
- Don't overtake long vehicles on the inside. Especially at/near a bend or junction. Please. Just don't. Ever. Seriously. This is how cyclists get squashed in the most horrific accidents.
- You do not have the right to move sideways into someone else's path. It doesn't matter that it is the only way to pass a parked car or avoid a pothole. You ... don't ... have ... the right to do it unless it is safe and you have checked it is safe. If it is not safe you should stop! The primary responsibility for your safety in this situation belongs to you, not the poor schmuck behind and to the side of you who is traveling responsibly at a steady speed, in a straight line, with clear road ahead of him.
I don't know what's worse. Those unaware of these dangers, those who are aware but do these things anyway, or those who argue against this basic common sense "because it's mah rights!!!"
If they could just master these two basic survival skills I could almost forgive all the other nonsense they do.