It is essential to consider reading as a social and cultural activity that is learned alongside an entire host of other activities that act to signify your place within your social groups.  Thinking of reading this way ought to allow us to divorce ourselves from the mystery of where meaning comes from, as in, "Why can this student understand what he just read, but that student cannot?" 

It is a game, with rules and meaning, not all of which are accessible to everyone. 

(This is why I like Brueghel's 1560 painting, "Children at Play.")