Reading as treasure hunt, rather than puzzle to be decoded
(May not be entirely coherent as am still terminally jetlagged.)
This riffs off the 'Secret Decoder Ring' panel at Wiscon, but is about the other direction that reading takes one - not the need to know all the references and allusions and influences of other stories or narrative conventions that the author puts in, but getting out new directions to travel.
(Also, to reinforce the fact that not knowing stuff does not actually necessarily diminish one's enjoyment, was browsing the copy of The Tale of Benjamin Bunny in Michelangelos on Monday evening, and a) as has often been commented, Ms Potter does not give a stuff about vocab appropriate for reading level, and b) WTF are muffetees? - even the OED online is not sure whether these are a kind of muffler or scarf or something in the mitten/muff line. Not knowing does not spoil one's appreciation, however.)
I think of all the books/stories that I heard about from reading another book - either the characters are specifically influenced by a particular text (Pilgrim's Progress in Little Women. e.g.); or they read other books (Jo reads, as I recall, both The Wide Wide World and The Heir of Redclyffe), or they mention some other book in passing (in Ann Bridge's The Lighthearted Quest, a romantic thriller of the 50s, she references Linda's bath with goldfish in The Pursuit of Love). Also various citations to The Constant Nymph and other minor classics of the early C20th.
There are also epigraphs - hands up everybody who first encountered The Way of All Flesh via T H White's use of the passage on 'a course of the larger mammals' in The Sword in the Stone.
Turning outwards, rather than in?
***
It is rather tangential, but it also occurred to me during that panel, and I never had the chance to articulate it coherently, that in mysteries you always get info-dumping (how members of country-house party are related, what were the security procedures for accessing the locked space in which body was found). Also that mysteries/thrillers are often a good place to go for insights into all sorts of ways of life that tend not to feature in litfic, such as various kinds of workplace.