Okay so I tried Valerian root last night around 10:00 am and I was wide awake until 3:00 am. Does anyone know why? I could have went for a run last night, that's how much energy I had. I only slept four hours as well.

Safety, Side Effects and Warnings:

The American Herbal Products Association (AHPA) gives valerian a class 1 safety rating, indicating that it is a safe herb with a wide dosage range.

Some people, however, experience adverse reactions to valerian. Rather than feeling the calming or sleep-inducing effects, they suddenly feel nervous, anxious and restless after taking the herb and may experience heart palpitations.

You can read all about it here.

Valerian Root - Benefits, Common Uses, Side Effects and Clinical Information for Valerian Root (http://www.anxiety-and-depression-solutions.com/articles/complementary_alternative_medicine/herbs_supplements/valerian.php)

Yeah I would say it has to do with some people's brain chemistry-neurotransmitters, etc... working differently.
Also if you have serious aches, drink a lot of caffeine, and other problems and habits can cause it not to work for you.