I have fond memories of taking a class with David Kelly and listening to his ranting about why 17 is objectively the best number. ("For example, the average length of a Giraffe's tongue is 17 inches! What more do you need?") He also hated the number 23 "because it's the mortal enemy of 17, I don't have time to explain why." While I was in the class the movie "23" came out: he urged us all to boycott the film, or better, form a picket line.