Over the last four nights, I have had several nightmares. Here's a sampling of what my brain is thinking about while I sleep:
-Osama bin Laden throwing knives at me in my parent's backyard (and hitting me several times).
-A shampoo bottle (somehow) exploding and causing massive destruction at my wedding reception. (Also, my wedding reception in this dream was in a 1970s-style rec room with brown shag carpeting, which is not the current plan.)
-A tornado destroying my house (I am saved by hiding under a pool table).
-Having a screaming match with my parents, complete with profanity, about how I find unreasonable their request that I microwave their pizza rolls at my house and bring them over to their house.
-Greg Kinnear trying to strangle me in my sleep.
-Having a conversation with Barack Obama in the back of a taxicab, in which I realized that he does not actually understand my concerns.
These may sound funny now, but when I woke up from each, I was terrified (or at least, as in the case of the last, severely disappointed). Anyway, because I have been thinking about the word "nightmare" more than I have since I was five years old, I started wondering about the etymology of the word.
Supposedly, the "mare" part of the word "nightmare" is derived from the Old English word "maere"--a demon or incubus that stands on your chest as you sleep, suffocating you. Similarly, in traditional German mythology, nightmares are caused by elves sitting on one's chest; the German word for nightmare means "elf dream." (Incidentally, these elves also steal newborn babies and replace them with deformed elf children.)
Read more here, here, here, here, and here.
Somehow this research has not really eased my mind.