The success of his children's books was to become a source of considerable annoyance to Milne, whose self-avowed aim was to write whatever he pleased and who had, until then, found a ready audience for each change of direction: he had freed pre-war "Punch" from its ponderous facetiousness; he had made a considerable reputation as a playwright (like his idol J. M. Barrie) on both sides of the Atlantic; he had produced a witty piece of detective writing in "The Red House Mystery" (although this was severely criticised by Raymond Chandler for the implausibility of its plot in his essay "The Simple Art of Murder" in the eponymous collection that appeared in 1950). But once Milne had, in his own words, "said goodbye to all that in 70,000 words" (the approximate length of his four principal children's books), he had no intention of producing any reworkings lacking in originality, given that one of the sources of inspiration, his son, was growing older.