The 'six month' time period is known among leftists as a 'Freidman'. New York Times writer Tom Freidman has said, continually, since the fall of the statue, that the next 'six months' will be decisive in how Iraq turns out.
This essentially proves that the American populace has a memory-span of four months or less.
Actually, that was just a random number I'm not suprised others have picked it up though.
As for a memory span of four months, I'm not suprised.