I'll tell you all two things that really makes my blood boil....
First thing: When I go to the petrol station on a hot day to fill up, and I have to park behind another car and wait for them to finish before I can use the pump. But instead of that person simply fuelling up, running in to pay, and then running back out (because they are aware that there is someone behind them waiting to use the pump) jumping in their car and driving off, they decide they are going to do their weekly shopping inside as well. So they take their damn time buying everything they need, sometimes taking a good 15 minutes, while more cars join the queue for the pump. We all sit in our cars sweating in the scorching summer sun, and then finally an idiot casually strolls out with bags of stuff in both hands, takes their time loading it into their car, slowly gets into their car and slowly drives off completely unaware of the long line cars that have built up behind them all that time. It really makes me mad. When you buy petrol, and you need to do some shopping, then go and pay for the petrol, then come back outside, move you car to a parking space and then go back inside to do your shopping. Don't leave you car at the pump, making the rest of us wait in the hot sun. I feel like taking a baseball bat to people that do this.
Second thing: When I have to stop behind a dozen cars for a red arrow at the traffic lights, and after waiting for what seems like forever, the lights change to a green arrow and the first car in line slowly makes the turn at a snails pace, ensuring that only 3-4 other cars make the turn before the lights turn amber. So the rest of us remain stuck at the lights for what seems like eternity. When I am first in line, I make the turn as fast as I can because I am aware of all the cars behind me, and I want to give as many of them a chance to make the turn before the lights turn amber. But I guess some people just have no decency, or are completely in their own tiny world.