I found a nice article by Karl Popper which I thought was worth it for this psychological point: If a theory is not falsifiable, then any piece of evidence "confirms" it, and so we may believe the theory has unbelievable insight and explanatory power. He mentions the fanatics of psychoanalysis, among others, but I could see it applying easily to mythology and religion. Here are his words.

"I found that those of my friends who were admirers of Marx, Freud, and Adler, were impressed by a number of points common to these theories, and especially by their apparent explanatory power. These theories appear to be able to explain practically everything that happened within the fields to which they referred. The study of any of them seemed to have the effect of an intellectual conversion or revelation, open your eyes to a new truth hidden from those not yet initiated. Once your eyes were thus opened you saw confirmed instances everywhere: the world was full of verifications of the theory. Whatever happened always confirmed it. Thus its truth appeared manifest; and unbelievers were clearly people who did not want to see the manifest truth; who refuse to see it, either because it was against their class interest, or because of their repressions which were still 'un-analyzed' and crying aloud for treatment."