The first time somebody told me they had it, I thought it was a joke. But, apparently it can be pretty debilitating, especially when trying to go to bed...
I notice that I move my legs around a lot when I try to fall asleep...
Restless legs syndrome (RLS, Wittmaack-Ekbom's syndrome, or sometimes, but inaccurately, referred to as Nocturnal myoclonus) is a condition that is characterized by an irresistible urge to move one's body to stop uncomfortable or odd sensations. It most commonly affects the legs, but can also affect the arms or torso. Moving the affected body part modulates the sensations, providing temporary relief. RLS causes a sensation in the legs or arms that can most closely be compared to a burning, itching, or tickling sensation in the muscles. Some controversy surrounds the marketing of drug treatments for RLS.
http://en.wikipedia.org/wiki/Restless_legs_syndrome