I had a boss who was an absolute twat. He was a lazy wee sod and hardly did any work. Anyway if he was pointing something out to me he would point with his index finger and pinkie. All I could imagine was taking a massive axe and chopping his fingers off. I know it's a bit extreme but it drove me insane. I used to go back to my desk and type swear words just to calm myself down. What annoying habits drive you insane?