Situation: I am standing in middle of both bookshelves on my left and right side while I figure out what book to take to my desk that is behind me.
Alternative situations: I am standing in the aisle of the two large bookshelves on their side of me, trying to decide which side is my book on that I want to get, the chair is behind me. I am in the middle of the corridor between the shelves walking away from the desk.
Question: Which direction should I go if I want to throw litter?