The motormouth who can't fucking tell that you want him to shut the fuck up while you have hundreds of pounds of weight on your back/above you
You nailed it. Other day on the bench, douchebag on machine beside me was going on and on about his problem at work for ten minutes straight. Twenty minutes later I'm in the other corner of the gym and he comes over beside me and now he's on the cell going on about the same thing. And he's talking loud so the whole gym can hear his problems. Totally oblivious to everyone around him.