I'm way too exhausted to have textbook insomnia, but I do have a sleep disorder that has me up and about in some kind of "twighlight sleep" where I'll do things like make myself something to eat and have no memory of it. (Sucks when cutting.) I guess it's like sleepwalking.
Back in the day when I used to smoke (cigarettes ) apparently I would light up one after another while "sleeping." To prevent me from burning down the house, we decided to try keeping them locked in the car, but then my boyfriend got worried I would go out for a "sleepdrive."