Media doesn't expire, but with increasing distance to the cultural context it was created in, enjoying any work in all its nuances becomes harder. Take for example Arrested Development - one of the funniest TV shows of this century, but unless you bring sufficient knowledge on the Bush Jr. administration, you'll miss the funniest layers of many jokes and stories.

And it gets all the more interesting to look back at how the Zeitgeist changed over time, as tropes evolve and tastes keep changing.