A minimal level of information is possessed by any normal person

From E.D. Hirsch's Cultural Literacy.

To be sure, a minimal level of information is possessed by any normal person who lives in the United States and speaks elementary English. Almost everybody knows what it is meant by dollar and that cars must travel on the right-hand side of the road. But this elementary level of information is not sufficient for a modern democracy. It isn't sufficient to allow us to read newspapers (a sin against Jeffersonian democracy), and it isn't sufficient to achieve economic fairness and high productivity. Cultural literacy lies above the everyday levels of knowledge that everyone possesses and below the expert level only known to specialists. It is that middle ground of cultural knowledge possessed by the "common reader." It includes information that we have traditionally expected our children to receive in school, but which they no longer do.