Hahaha I am having lots of fun with this thread!! (or should I say, HAD?)
Is this M Kelly really serious? I don't think so... ;o)
I won't try the riddle anyway because English is not my native language, and even if it was, I am not very good in riddles....
I remember seeing this in a Readers' Digest children's book published in the 50s! Not that it was the 50s when I saw it, mind. Regardles, the answer went as follows:
John, where James had had "had", had had "had had"; "had had" had had the teacher's approval.