Means something’s properly winding you up, stressing you out, or making you feel like you’re losing the plot. You use it for anything relentless, loud, fiddly, or just plain thick, from annoying people to broken apps to chores that never end. It’s a go-to moan when your brain’s had enough and wants to tap out.
"The lad in the office clicking his pen all day is doing my head in. I’m this close to launching it out the window."