I could not stop myself once and went roud all the (ladies) loos at my gym correcting all the typos and grammatical howlers on a poster on the back of the doors. I'd been staring at the them for months, seething, before something finally snapped. I figured I could blame hormones if cornered in possession of a marker pen(was 9 months pregnant at the time,so had been going to the loo A LOT!).
Drives me insane - like nails down a mental blackboard!