It is one thing to take inspiration from another's work for one's own creative writing, but it is entirely another to complete a work first conceived and named in another's fiction. What to make of such fictions within fictions?  

Critics have long held that, even if Cervantes was at least somewhat aware that his work would be successful, this was only because he knew it was funny, and hoped that, in reading it, as he famously wrote in his first preface to Don Quixote, "the melancholy would be moved to laughter, and the merry made merrier still."