Dispantia
(noun) The medical condition, which often afflicts males on television, where one is unable to remember if one is wearing pants. Symptoms of this include, not only the lack of pants, but also to go sans trousers in public and the inability... ...to remember (or sluggishly recall) not wearing pants at a later date.
Sally Sparrow was in for a surprise when she visited her friend, who neglected to inform her that her brother suffers from Dispantia.