Periodically I seem to suffer from an annoying insomnia. It manifests not as an inability to fall asleep, but rather as an inability to stay asleep. I went to sleep last night at around 12:20, but then woke up at 3:30 and was unable to go back to sleep. Dawn came. Still not sleeping. I sat and read. No sleeping. Finally, I gave up. But now I'm having an exhausting, unproductive day on only 3 or so hours of sleep. Argh.