Supposedly losing-your-teeth dreams mean high anxiety, so it’s no surprise that I’ve had more than a few of them. Bloody gums, teeth falling through your fingers kind of dreams. Teeth turning into shards of glass dreams. Yes, those dreams. The most memorable of them, perhaps, being the one in which, against my will, I snipped off my front teeth with nail clippers. Maybe the only sorts of dreams that bother me more are the things-happening-to-your-eyes dreams. I’m explaining this because in the first few minutes of Don’t Be Afraid of the Dark, a film written and produced by Guillermo del Toro, a twitchy old man with a hammer and spike knocks the teeth out of the mouth of a screaming woman pinned under his knees.