Your mouth is moving while your mind is working overtime. An epiphany can result, or maybe foot-in-mouth disease, or an unraveling mess. Newt Gingrich is always fun when he does this - the combination of a hyperactive Machiavellian mind and a man who loves the sound of his own voice; he briefly made orphanages a national talking point after he tried to ad-lib a defense of his party's policies vis-à-vis welfare reform. Thinking out loud is best done when you can think on your feet.