Every single piece in a 1000 piece jigsaw is important in the overall scheme of things. Missing just one piece compromises the whole experience. That's why we go to such lengths to ensure that every sealed bag has all of its pieces. That's why we recommend that you think twice about running the vacuum cleaner until every piece is in place; that you keep an eye on your brother, especially if he's the competitive sort; and that you NEVER EVER let your pets help. (We're not naming names, but we know from experience what sticky paws, static electricity, manic curiosity and plain old good-natured clumsiness can do to the whole puzzling experience. You know who you are, Dickens.)