 Geisel variously stated that the book took between nine and 18 months to create . Donald Pease notes that he worked on it primarily alone , unlike with previous books , which had been more collaborative efforts between Geisel and his wife , Helen . This marked a general trend in his work and life . As Robert L. Bernstein later said of that period , " The more I saw of him , the more he liked being in that room and creating all by himself . " Pease points to Helen 's recovery from Guillain – Barré syndrome , which she was diagnosed with in 1954 , as the marker for this change . 
