Tele-cognizance is the realization that one is a fictional character "living" in the TV Universe. Although it could be considered a form of enlightenment, for some it could be an affliction. When David Addison of 'Moonlighting' would break the "Fourth Wall" (which serves as the viewing window into Toobworld for the audience viewing at home in the Real World), those around him just thought he was wacked.
But when Denny Crane of 'Boston Legal' does it, his partners in the law firm mistake his tele-cognizance for a symptom of Alzheimer's.
Tele-cognizance is contagious. Alan Shore, a friend and colleague of Denny Crane's, has exhibited the trait as well. Alan probably contracted the same strain of tele-cognizance that Denny had due to their close - sometimes too close! - friendship.
Because Denny Crane gave a great display of tele-cognizance last night in the second episode for this season of 'Boston Legal', Maria Elena Fernandez of the L.A. Times has a great article about tele-cognizance (not that she used the term!), and you can find it here.