5. References To The Eleventh Doctor
The Eleventh Doctor is not only the only Doctor to have an episode named after his number (his debut, 'The Eleventh Hour'), but he's also the only one to be stalked by two number ones. If you look closely enough, elevens are littered through his tenure like plot twists in Journey to the Centre of the TARDIS: Matt Smith dons a number eleven shirt whilst playing football with Craig, his hotel room door in The God Complex has a number eleven on it, and he declares to Rory that they're in "11/10" much trouble. Only twice has anyone ever said out loud that he's the Eleventh Doctor, but Moffat clearly understands that we've named them One to Twelve for shipping purposes, so if he could drop an "Eight point Five" reference around John Hurt, he'd make Tumblr a tidier place tag-wise.