- I like using up the last of things.  When I get to the end of a tube of toothpaste, bottle of shampoo, or carton of orange juice, I feel a strange sense of accomplishment and get enjoyment out of crushing up and disposing of the container.  None was wasted and it's one less object taking up room.  This is especially true for anything in the bathroom taking up room in the shower or in a cabinet.
I feel the same way about this.  The same goes for grading tests or papers.   It feels good to get that last one done.