Did it... Caught the corner of the slide with my noggin!

Ha Ha, just did that last Sunday. Was getting the coach ready to move to another site and walked right into the damn thing..... No blood, not even a scar but is put me on my butt! My wife heard it inside the coach and went looking for ice but there wasn't any so she brought me a bag of frozen meatballs. I hit the side of the slide, I am trying to think of something that will work to make me remember that the slide is out. Any thoughts?