There comes a point in every British man's lifetime when he has to explain Dr Who to his American girlfriend. How do you explain the tale of an odd man who hangs out in a phone box, keeps getting younger and has been scaring kids since 1963? How do you describe the succession of eccentric, obsessive adversaries? What sense can be made of the fact his infinitely-large spaceship is actually the size and shape of a police telephone box? How do bring up that you used to be terrified of the combination of Daleks (squidgy blobs in armoured wheelchairs with broken megaphone voices) and the start of the closing theme tune (which felt like all of space was falling on you)?
I did tell her that after every couple of series, the doctor regenerates himself (i.e. is replaced by a younger, less eccentric actor) which has happened about ten times now. "Wow," she exclaimed. "So by now he must have covered most ethnicities and both genders." Cath has a lot to learn about television.