I'm just going to come right out and say it: Potty training sucks monkey butt.
Especially when you have a used diaper on the floor, right next to a set of pants. This means (a) there is a toddler running around your house somewhere pantsless and completely without the insurance of a diaper. And (b) Your house is now the most disgusting place you've ever been. (short of a truckstop bathroom)