I love the people that check behind the shower curtain before using a restroom. As I see it, there are a couple (more than a couple, actually, I'm just too lazy) flaws with that plan:
First of all, why would you even do that in the first place? What on earth would be behind the curtain that wouldn't just ambush you as soon as you entered the room?
Second of all, what would you do if there was (on the extremely off chance) someone or something with bad intentions behind the curtain?
Let's be honest, that's just silly. (Now excuse me while I check under my bed for dead bodies and in my closet for dinosaurs.)