I think the division goes well beyond the construction of the wall. It is the West/East thing that goes back to feudalism and the advent or urban mercantilism. In Western Europe, feudalism perished in the 13-14h century, replaced by urban mercantilism and the urban/cosmopolitan culture associated with it. In Eastern Europe, feudalism with the associated dominance of landed elites overseeing the "idiocy of the rural life" persisted in one form or another until the 20th century. The border between GDR and the Federal Republic fell on the demarcation line separating the urban/cosmopolitan West and the feudal/parochial East.
As Max Weber aptly observed in _The Protestant Ethic and the Spirit of capitalism_ - this division is a deep cultural divide, not just a demarcation line between states.
Wojtek