You've probably met him. You'll be belting along or down a road when he races past you in an overtake move surely snagged from professional motor-racing it's so tight. Moments later, turn signal on and he's turning right, right in front of you (UK readers - he's turning left), forcing you, if you're paying attention*, to slow down for him. Seeing as he was going to have to brake anyway, all he needed to do was tap the brakes a few seconds earlier, and (gasp and shock) WAIT a few seconds for you to get past the road or entrance he had to slow down to turn into, instead of rushing around you and being a hero.
**** you, impatient idiot.
*extra pus-filled flea-bitten love for those ****ers who don't bother with the turn signal. So you've got this guy who comes roaring past, you figure with that kind of effort he's surely going to be going some distance down the road, no threat, and OH HELLO suddenly he's just thrown on full anchors and you have to brake and swerve around him not even sure why he's stopped.