In the beginning?

The scene: Jacob is pulled over for speeding in the hallway.

Me: "Jacob!"

Jacob, nervously: "Yes, sir?"

Me: "Jacob, can you ever remember a time when there wasn't a rule against running in the house?"

Jacob: "Nooooooo."

Me: "How long has that been a rule?"

Jacob: "Ever since when the world was created!"

And in my head I could hear Adam having this same conversation with Cain and Abel.