No Good Deed Goes Unpunished

Yesterday, I decided to help my kids by thinning out the family history files I have accumulated over the past 30 years and stored in a four-drawer metal file cabinet. I worked all day, tossing a kitchen trash bag full of paper out of the top drawer. When I finished, the drawer was still full. Which one of you people has been sneaking behind me and filling the drawer? Or is it a magic file cabinet?