I was trying to read my way through the Atlantic last night--this is one of my substitutes for sleep--and because the Atlantic is often dull I began to think instead about all the stories where sleep is the trigger for transformation. Often not a very nice transformation, but what do we expect? Sleep itself is problematic--it isn't the opposite of wakefulness so much as a dress rehearsal for death.
I have a neurological disorder that is often misunderstood as a sleep disorder, and misunderstood further because it has a stupid name: restless leg syndrome. People who haven't experienced it tend to think it's trivial, but it's not; it's torture. Even with all sorts of nauseating medications, originally developed for people with Parkinson's, I average two to five hours of sleep a night. I once had a sleep study done and the poor sleep-lab tech wore himself to a frazzle re-gluing wires and coping with a squirming, kicking, bumptious subject who produced, according to the report, a whopping 67 minutes of non-REM sleep. Never got to REM because I hardly ever do--apparently I'm not much of a dreamer.
I don't bring this up to snivel, but to notice that in stories sleep tends to be linked with danger--it's when you let your guard down that the slasher intrudes or the spell activates or the golden key gets stolen. These kinds of stories are truthful, and their truthfulness is most apparent at 4:15 a.m.