There was a Simpsons flashback episode where teen Moe places a prank phone call, and then turns to the camera and says,
"So, uh, dat's the origin of dat."
I'm playing Bioshock Infinite: Burial at Sea. I just reached a room whose sole purpose was to explain why the magic powers in the original #bioshock were injections, while the magic powers in the (chronologically earlier...sort of) Bioshock Infinite were drinks. And I could hear the game saying to me:
"So, uh, dat's the origin of dat."
Fortunately, Burial at Sea also has some nice explanations of things that really do add depth and insight, most notably (avoiding spoilers here) why a character in Infinite acted in a way that seemed a bit out of character, and that in turn prompted another character to act in a way that was out of character.
And I just hit another audio diary, much later in the game, to answer the same question again. Were there legions of fans demanding to know why two different worlds had two different vehicles to deliver powers? #bioshock
Thinking about it some more, I think what gives me the sensation of "So, uh, dat's the origin of dat", and this goes for the Simpsons example, the Bioshock one, and other places where I've had the same reaction, is a piece of filled-in backstory that explains something that you never really thought needed explaining, while not adding any particular depth or insight to your understanding of it.