I rarely encounter anyone that knows the first thing about the dominant narrative, much less why they believe it. My experience with those who have not taken (and likely never will take) the time to deconstruct the official narrative have a worldview that can be characterized thusly:
I trust authority.
Media (TV news, newspapers, magazines, any part of the 6 conglomerate mega-source that delivers all of the perception management narrative - let's throw in government institutions and academia for good measure) is an authoritative source of factual information.
Therefore I believe the narrative presented by the media.
Ironically, these same people may also poke fun at those with religious beliefs.