Cleaning is something that you need to do from time to time. It feels good when it is over, and hurts while you are doing it. I do a round of cleaning every 3 to 4 months, always having the same things happen.
Finding movies/game that you bought but never watched/played. It seems I own a copy of "Force Unleashed 2" for Wii, no memory of buying it. Assuming I got it the same time I bought "Paranorman", which I saw in theaters, it was good, not sure when or why I got the DVD. Ever time I clean I find something and go "When the hell did I buy this?".
Reorganizing shelves that I haven't touched since last time I cleaned. There is a thick layer of dust on everything on this shelf, clearly it has not been touched for months. but someone if I move things into just the right place it will prevent dust from accumulating in the next few months.
Find small sums of money. Change under things, a dollar here, a five there. Never very much, but usually enough to treat myself to a fast-food meal. Kind of a built in reward for cleaning I guess. Here again, I am not sure how this happens, I am a stickler about emptying my pockets in the same location when I get home, so where does this other money come from? I don't have many visitors, so this is a mystery.
See many items I have no practical use for, but won't throw away. I need the Beer-Buddha for some reason. And that those VHS tapes that I no longer have a way to play. YES I NEED THE ATARI 2600 CONTROLLERS, AND I DON'T OWN A 2600 OR ANY GAMES FOR ONE!