I mean, take USA for example, is it even the same country after each amendment? After a Civil War? Civil Rights Movement? Landmark Court Rullings?
One could argue that Modern America began in 1965, with the passing of the Civil Rights Act. Or in 2001 when the Patriot Act was passed. Or in 2009 with Citizens United Court Ruling. Or in January 2017 when… you know. Or in January 2025.
When did the country really start?
Even more far fetched: Italian fascism considered itself the continuation of the Roman Empire (the middle ages did not count, somehow). Does it mean that they were 2000 years old for a bit? But then, nowadays Italy consider itself the descendant of fascism (with a tinge of shame) but not of the Roman Empire. Can we pick and choose our lineage?
China consider itself ti have been a consistent country since (handwave) basically forever. Is that enough?