I have no idea why, but it seems to be the fashionable thing to do here nowadays.
Oh come now, I'm sure you can think of something...
You left the toilet seat up.
You left the ice cube tray in the freezer with 1 cube left
You ate all the cereal and put the empty box back in the cupboard
You put the toilet paper roll on backwards (which is really subjective, I know--but you were probably wrong anyway)
You argued with your spouse--granted, they weren't in the room to hear it---but it's the principal of the thing.
You left the baby carrier on top of the car and drove off. Mind you, the baby was still in the house because you forgot to put junior in it, so you're screwed either way on that one.
..so really the posibilities are endless, you're just not trying hard enough.