That's a good hypothesis. Unfortunately this doesn't come from asking people, "How do you know when you're rationalizing?" or any variant thereof. The original problem arose when we could not for the life of us convey to some individuals why the Litany of Tarski might be useful. We gave examples from our own lives and watched these individuals just blink and say, "Huh. Yeah, I guess I just don't relate to that at all."