The Eternal Insomnia Saga Continues

For weeks upon weeks I've had trouble sleeping. Endless nights spent sitting outside in the dark or aimlessly wandering around the house. Midnight, 2 am, 4am, it doesn't matter, I'm always awake.
Last night, with no intention of sleeping, I crashed, completely, before 9:30, only to be startled awake at 12:30 by the sound of a door closing. Nervously, I got up to check out every room - after stopping in the kitchen for a knife (figuring I'd at least go down fighting). I didn't find anything but I was still jumpy. For the normal person you'd think this would make it difficult to go back to sleep but, Oh No!, no me - I don't remember anything else until 8:30 this morning.
Lesson learned? The secret to curing insomnia is this: Have a reason to stay awake and then think that scary aliens are in your house. 11 hours of deep, deep dreamless sleep are guaranteed to be yours.