Okay, this one is dumb, but it bugged the hell out of me this morning.
I hate when you're running late, but you know you need to stop and get coffee (because if you don't, you'll be comatose before noon.) Then you get in a line behind 46 people, each of whom can't decide which flavor of doughnut (when there's a grand total of 4 choices) they want. Then they all want to pay in pennies. Then their cell phone rings, and they answer it before paying, holding the line up more. Then they STAND AT THE COUNTER organizing their purse instead of moving to the side to let the next person order. Then, after it's all said and done and you have your coffee and you're driving away, you realize that they forgot to give you any cream.
I hate that.