Installing ceiling fans. Sitting on the floor in the middle of a pile of blades, tiny screws and washers, try to cram 25 feet of wire and a half dozen wire nuts into the light kit canopy.AUUUUGGGGHHHH!
"Hey, could you drop what you're doing and go change that light bulb?"
Cracks in my fingers
Pinching my fingers in my strippers or pliers
Playing hard-hat ping pong in the middle of plumbing pipes, trusses, EMT, etc. for 15 seconds to find a sweet spot to stick your head so you can look at what you're working on