You know, in a standalone, original work of fiction, having characters reference things beyond the story is generally seen as a good thing, a way of giving a believable sense of a larger world beyond what's on the page or on the screen. In life, you don't always know the whole story behind what the people around you are saying or doing, so that sense that a character has their own ongoing story taking place offscreen, or a history that we only get a glimpse of, helps give realism and texture to the tale. But you do the same thing in something that's known to be an ongoing series and people complain about being "required" to read everything that's referenced. That's bull. You don't have to understand every last reference in a story. Sometimes not understanding them is the point. (How much less fun would it have made Calvin and Hobbes if we'd actually seen the Noodle Incident?) Knowing that there's stuff in the fictional world that you don't know helps make it feel like a richer, fuller reality.
