Customers moving 2' every time I move 2' at a bid.
Employees who need to be told to get out of the crush zone/ danger zone for no reason, then go in the worst direction, such as away from where all the productive work can be done.
Having to tell the spotter, when I'm backing a trailer uphill and around the bend, that I can't see through the truck, I'll never ever be able to hear their hands while changing back and forth from looking at two mirrors, and the windshield, and "STOP!" means "stop", and "okay" is about meaningless, unless I can read their minds.