If you finally get all the laundry washed, dried, and folded ... the children will suddenly emerge from their bedrooms with a secret stash of dirty clothes to refill the laundry hampers.
After all, a hamper can't sit empty for more than an hour. It's a law.
(If you're looking for the previous 597 rules, there aren't any. I chose a random number. But I will be adding more housekeeping rules, as time goes on.)