There are but a few books which can touch both the hearts of kids and adults alike. But The Missing Piece series does just that. Shel Silverstein has indeed managed to fuse a general theme of self-appreciation with these remarkable books that does not come off as appealing to kids but also puts a bite into an adult heart once read. The Missing Piece series comes in two different book installments. The first one was entitled "The Missing Piece" while the other one is entitled as "The Missing Piece Meets the Big O."

In the first book, the main character was this Pacman-looking circle who was in search for that lost pizza-like piece which will complete its being. Whether the piece is a he or she, there was no direct indication. In both stories, the character searches for that missing triangle and tries to look for it in different creatures and places. In the first book, the lacking circle tries to roll along to find its missing piece and asks creatures along its way if there was any lead about the missing piece. It also has this catchy yet sad song which it hums along as it searches for the said piece.

The moving thing about the book is that the circle finds different pieces along its way, trying to see if they fit perfectly by rolling with that piece for a specific time. But in the end, each of the pieces seemed to not really fit the circle so the latter ends up parting way with these pieces. Another noteworthy thing about the book is its ending. Although the circle's main purpose is to find its piece, it does so in the yet the circle decides to put up with it no more. It finds fulfillment in its own skin because of very valuable and though-provoking reasons. Kids will also love the book because of its simple phrases, the catchy song, and the simple illustrations which are very easy to understand.

This theme of self-fulfillment and acceptance is once again seen in the second book installment of the series known as "The Missing Piece Meets the Big O." This time, the main character is the missing piece which was left behind by the Pacman-looking circle. But in this book, the missing piece has not yet realized the important value that the circle had accepted. The book once again captures the hearts of kids with its simple illustrations and simple to understand phrases. Once again, it will capture the hearts of the adults who read it because the book is about relationships. It gives importance to loving and understanding one's own importance first before he or she can flourish further in meaningful relationships.

As the missing piece meets the big O, it learns what it takes for someone to become fulfilled. It realizes the beauty that it has on its own even without a bigger piece to take it on a journey. The big O has become a mentor for the missing piece to understand itself and love its being without the need for another piece to complete it.