First book I ever bought. At the Boys & Girls Club, in the library when Connie Constance ran it, at a book fair. I think I was 6. My copy survives, aided by about half a role of masking tape. I'll have to show this one to my nephew and see what he thinks. I never really cared for the story myself, or the art. It's good but not great. The message is nice - picking up after yourself is important, or else a mess will amass and messy monsters will be confected. But I was always proud of The Messy Monster. It was mine. In fact, this just might be the first thing I ever bought, ever. Which is crazy...