I remember this book so clearly from my childhood. It is very easy to read for beginning readers with nice illustrations. It explains that books borrowed from the library are not yours, and that they should be treated with care and returned on time. As a very young child I was upset that people might treat library books badly and make Mr. Wiggle unhappy. I was so upset about this that my mom and I wrote and drew our own Mr. Wiggle book where all the children treat the books well, and Mr. Wiggle is always happy. Lol. :) This may have started my life-long reverence for books. Even in my own books, I never write in them, underline anything, or even dog ear the pages! Mr. Wiggle would be proud of me.