Was it a senior moment? A sign of some medical problem?
Physicians said it was merely the type of gaffe that can happen to anyone, though these mental fumbles can become more common with age.
Perry, just 61 at the time, had the misfortune of forgetting the name of the Department of Energy on national television. It was one of three agencies that he had proposed abolishing.
A good sport about the whole episode, he reacted to the gaffe with humor.