Also, I'm betting it was a self-discipline thing, but it seemed like they'd never let us take a pee until our little bladders were ready to burst...and I remember at least twice where guys couldn't hold it any longer and let loose. One was midway through boot camp, and we were at parade rest in a parade formation for bigwigs - taller guys up front as usual. Being a couple of rows back, some of us heard - and then saw - the liquid running between one private's legs as his legs quivered a bit; Sgt. Landers heard it too, because he halfway turned toward him, turned beet red, and told him his ass was grass as soon as formation broke.
I really don't remember what happened to the poor guy, but I'm sure he recalls it to this day, assuming he's alive!
Bad enough to have it happen during training, eh? But in an actual parade situation, Lord have mercy. I don't think it's very often taken as a literal translation when someone remarks, "You'd pi$$ yourself at boot camp." Rather, I think it's often taken in the abstract ; )