I believe that they believe it--and I also believe that they seem like fairly normal human beings, but it is a lot easier to fake being normal than it is to fake a moon launch--

Most people, especially most Americans, know a lot about whatever it is that they do for a living and have a fair grasp of the facts, along with a bunch of reliable opinions related to that stuff, but when it comes to everything else, they are all over the place--most have no undertanding at all of the processes that bring them food, take away waste products, provide them with clothing, let alone how their mortgage rate was caculated, or where the money that paid for their home actually came from, or what goes on in any of those 315 odd other countries on the Rand McNally globe in their library--They don't need to know, they don't wanna know--

When called upon to come up with explanations for stuff that they know nothing about, some people just shrug, and others just make answers up--technically speaking, this is called, "confabulation"--though non-technically, it is called being "Full of shit"--