"Oh Shit" moments...

I just refrain from insults*. They just mean that I get angry, and the other person gets angry. I suspect this does not make the world a better place. If the person acting stupidly is genuinely stupid then pointing out their stupidity is unlikely to help, since they will simply carry on being stupid. If they're not stupid then it'll either be a one-off they won't repeat or they'll work it out for themselves.

Rather than resorting to insults, when annoyed by the stupidity of others, I roll my eyes skywards and tut. When truly exasperated, I might even shake my head dolefully and sigh. Hanging on in quiet desperation is the English way.

• I do not always succeed in this task. I did call the man sitting next to me on an Easyjet flight a few weeks ago a cunt. But he deserved it. There's only so many times I can be elbowed, hard, in the rib-cage for no good reason while I'm trying to sleep before even head-shaking and sighing becomes inadequate.
  
  

Fair point. I don't always succeed either. There was a prime example of "driving license with pack of cornflakes" driving last week which managed to get my goat. A mouthed "idiot" and bird flipping resulted.

But it was probably somebody who didn't care what others think anyway, else they wouldn't have swerved over lanes for about a mile and nearly caused a collision while changing lane. Your "too stupid rule" probably applied :)

I guess to me the frustration is "where is the police" and "why did I have to suffer for 10 months to get my license and see this idiot" whereas it's better to treat it as a natural phenomenon that strikes when it does.

"The wind of the cuntish driver". "it's raining legally blind idiots". Etc.