Ugh, really?  The one time it happened to me, it was a fucking perfect storm of unfortunate.  Had been sick, needed a shower, dropped the soap, bent down to pick it up, and sneezed all at the same time time...whoops, shit myself.  Needless to say, I was fucking mortified, and used a whole gallon of bleach on that tub to clean it.  How does one go through life not giving a fuck about shitting in a tub?  Oh wait, hams...