Why can't I sleep?

That's a question lots of other people are asking themselves right now.  

According to http://www.emedicinehealth.com 

30 - 50% of the general population has insomnia. The percentage is even higher among alcoholics, the aged, and mental patients.  I used to pride myself on being just another sad statistic among the general population, but lately I think I'm beginning to slip into one or both of the last two categories. I'm not an alcoholic, but I might consider it if I thought it would help.  

That same article says insomnia is a sympton, not a standalone disorder.  Great. Now  I have something else to worry about: a symptom of WHAT?  Sounds like it could be just about anything.  The site lists at least a hundred possible causes, ranging from jet lag to brain tumor.  Wait...there's a section on food, too. What you eat can keep you awake.  Well, I knew that. Chili keeps me awake, for instance. But I didn't eat chili tonight.

The medical articles don't mention email, facebook, twitter, or blogging as possible causes.  Are they causes? Or does insomnia itself result in excessive online involvement?

Am I excessively involved? Or just trying to keep up....

Never mind. I'm going back to bed. Right now.