I'm sorry for the foul nature of this post, but why are so many people so filthy and otherwise discourteous in public bathrooms?

Do they urinate on the seat at home?

Do they leave without flushing at home?

Do they throw toilet paper and towels on the floor at home?

Do they leave the water running at home?

And why do they think it's okay to have a conversation while people are on the can? Or, much worse, have a cell phone conversation while they are?

All of this disturbs me. Should I really have to put a note in the bathroom to flush the toilet before you leave?