Has there really been no technological advancement in Westeros over the thousand of years since the Age of Heroes? I mean the earliest scenario in which we can start is 'The Bleeding Years' and houses like the Starks has ruled for thousand of years before that scenario as Kings of the North. How different is the timeline of the books from the bleeding years or even way before that? Surely some innovations must have been made but how much has life changed in Westeros over the many milleniums?