Ah, there's nothing like a nice warm, relaxing shower, is there? Well, there's the shower when you go to soap your 2000 parts and notice the once magnificent bar of Zest has been reduced to a sea-green splinter. You can't leave the shower in search of a new piece - your stuck, alone, and wet, and disappointed. How can you even get any use out of it? Try to rub your hands together with the bar, it just causes friction and makes the precious ration of soap even smaller. Okay, well, I'll try to rub it straight on my body - oops, I dropped it, oops it cracked in half, oops got sucked in my butthole. Just accept it, you will just leave the shower angry and sub-clean.
If I was in charge, leaving a bar of unusable soap sliver in the shower will result in the death penalty via shooting squad. No questions asked. They had it coming to them in the first place.
I Rule.