I woke up mysteriously in the middle of the night last night, depressed and upset. I know what it was about, or at least what it was hanging on (misleading one-word summary: loneliness), but I don't know where it came from - the past couple of weeks I've been feeling especially happy, energetic, productive, and optimistic. Maybe it was just leftover emotional weirdness from a dream I can't remember, or something.
In any case, the mood passed in half an hour or an hour, but I couldn't get back to sleep again for about 4½ hours. So I'm not at my most functional today. :-)