I twisted my ankle in my sleep...
 

... apparently. I must have sleepwalked, because I woke up with a twisted ankle and I didn't go to bed with one. :(

Oh well... It could have been worse. At least it's not broken.

I think it was the underpants gnomes playing a trick on you. Twisting and twisting as you slept. At least you didn't wake up with your ass hurting.