Oh man, another rule of cool: I’m honestly not even sure how I feel about this one. It came about as I was pondering a topic from a while back about someone wanting 20k, and another frater said “that exists, it’s called Dune.”
It reminded me of the great expanse of time between us and 30/40k, and how, especially in the HH, we get little references here and there to literature that predates our real world, modern era.
Like the Ultramarines quoting Clausewitz, or Perturabo knowing about Da Vinci, or I don’t remember who talking about Shakespeare. Or a religion called Catheric.
While I never quite hate mentions like this, I’m never entirely comfortable with them either. Given the great son of time, even though there is technology, I usually think that there should be no way that we modern readers should have any familiarity whatsoever with the setting, even if all we are getting are throwaway mentions.