How do kids think of these things?

I ran into an old friend the other day. His family consisted of 2 boys and a girl who all grew into their teens about the same time. While we were talking, we thought about the time his parents went out for the night, told everybody to behave themselves and left us on our own (I was a guest). It was raining that night, and when Skip let the dog out, his sister reminded him to clean the dogs feet before she came in. I don't know what made him think of this, but when the small dog came to the door, Skip held the dog over his head with it's paws touching the ceiling, so that the dog left little muddy prints on the ceiling. His parents wondered for over 20 years how the dog prints got on the ceiling.