Car parks.  Is it childish of me to want to have some stickers made so that I have them to hand to put on windscreens of people that missed the part of 'how to park'  when they learnt to drive?  Instead of parking within a bay like a considerate person, they either park right on top of it or just over it, either way, stopping anyone else using that bay.  Driving the opposite way on a one way, how many signs do they need?  Then getting irate when I kindly indicate that they are driving down the wrong way.  Hmmmm, now, what to put on the stickers.  'Learn how to park you fucking dolt.'  Think that should get the message across.  In the words of the late great Kenny Everett aka Mr Angry 'oooh I'm so angry'!