There are no dust kitties under any of the furniture.
There is nothing in any of the dishracks.
All the toys are in their proper bins.
There are no little fingerprints on the walls or doorframes.
There are clean sheets on all of the beds.
All of the laundry is done, folded, and put away.
All the closets are clean and organized.
So far as I know, there is not one dirty tissue hiding anywhere it shouldn't.
It hasn't happened since erev Pesach 2006. Who knows when it will happen again?
But for one... beautiful... moment...
My house is clean.