The general vibe of Last Christmas was Alien meets Inception meets Miracle On 34th Street meets T'was The Night Before Christmas meets pretty much every other Christmas story ever in between. Once again Steven Moffat handpicked the best of the rest and shoved it altogether for one timey-wimey extravaganzathon featuring Santa Claus in the North Pole, elves, reindeer and, of course, a bunch of dream-dwelling demons that gave all the characters crabs. Don't pretend you didn't think it. The Dream Crabs were revealed as slimy and telepathic creatures who ambush their prey by feeding off the images of themselves in their victims' minds. It's not all bad news, though, because while they're drilling into your brain to liquify its contents for their own consumption, they do take the time to induce you into an anaesthetic dream-like state so you don't feel a thing. A pretty kind gesture, really. It's the least they can do. But just how many dreams were there in Last Christmas? If our calculations are correct, there were four. Clara's rooftop which led into the Arctic Base, the Arctic Base after the crew were attacked, Clara's "Last Christmas" with Danny, Clara as an old woman and then, at the end of the episode, everyone was finally awake as the Doctor and Clara went off on their merry way. You can be forgiven for nodding off yourself whilst trying to work it out, so let's just say that none of it, until the last scene, was real. As the Doctor himself wisely pointed out in the episode, the problem with fact and fantasy these days is that they're both pretty hard to believe.