He is an active guy. Putting a roof on the building, he struck his finger while hammering. It hurt plenty. Then, a minute or two later, he struck the same finger again. We were not witnesses to the event but some of the animals nearby report hearing shouted expletives high on the scale of severity.
One trouble with expletives is that they are damaged from overuse. See for example, this passage from Donald Westlake's book "Watch Your Back":
The father waited, but the son merely loaded up with some Froot Loops and glowered at the countertop, so at last the father said, "So? What happened?" "The fuckin truck showed up," Mikey said, speaking through pastel pieces of grain, "but then somebody fuckin wrecked it." "Fuckin wrecked it? What, the fuckin driver was drunk?" "It wasn't the fuckin driver," Mikey complained, taking on more pastels. "He got outa the fuckin truck, some other fuckin guy got into it, drove it the fuck off. We never even got a look at the fuckin guy." "Drove the fuckin truck off?" "Ran it two fuckin blocks," Mikey explained. "We're racin the fuck after it, you know we are. Then this other fuckin guy shows up, some other fuckin car, gets out with a fuckin axe, takes the fuckin axe to the fuckin tires, cuts them all to fuck." "And what are you fuckin guys doin?" demanded the father. "Standin around with your fuckin thumbs up your fuckin asses?" "Nicky and Petey went after them in the Audi," Mikey said, "but then this monster fuckin guy with the axe, he throws the axe at Nicky and Petey in the Audi, and the Audi rams into the back of the fuckin truck and the whole thing goes up in fuckin flames."
The hammerer explained to some innocent teens who had no familiarity with the over-used word in the quoted passage above that when he felt the pain of a hammered finger, he had exclaimed,"Gee whiz! That hurts". He alleged that striking the same pained finger a second time caused him to exclaim "You silly guy!" The teens are said to have expressed doubts that he was quoting himself accurately.