Famed indie producer J. Robbins (Jimmy Eat World, Against Me!) discovered that the hard way while playing lead guitar with the seminal D.C. hardcore band Jawbox in the early 1990s.
He was having fun, bouncing his guitar off the ground and playing it when it rebounded. But he mistimed the bounce, and the ax smacked a hole in his forehead.
"I was like, Why is my sweat like syrup? That's so weird, it feels real heavy," Robbins says. "And then [I was] looking at these people who were right in front of the stage, and they've gone pale and are like, 'Whoa,' 'cause head wounds bleed an awful lot, you know?"
Unfortunately, this didn't teach Robbins his lesson.
"Moments like that tend to backfire more often than not," he says. "I mean, I had a Fender Jazzmaster that I really loved, and something was fucked up with the jack, and I was just freaking out because it was onstage and I was like, 'The gods are conspiring against me again.' So I just threw it, and it snapped the neck.
"There's no lesson that can be taken from that. When you fuck up, it's impossible to go and paint that in a good light. I'm just like, 'Well, I guess that's just self-expression . . .'"