It comes from a passage in "The Cleanest Race" by B.R. Myers[1], which I recommend as a lens into the internal effects of North Korea's propaganda

>"One colleague told me he finds the North Korean personality cult too absurd to take seriously; indeed, he doubts whether even the leadership believes it. But no regime would go to such enormous expense, year in, year out for sixty years, to inculcate into its citizens a worldview to which it did not itself subscribe. (The only institution in the country that did not miss a beat during the famine of the mid-1990s was the propaganda apparatus.”

There was another book on North Korea which corroborated this statement with actual numbers; I'm having trouble pulling it up at the moment.

[1] https://www.amazon.com/Cleanest-Race-Koreans-Themselves-Matt...