I have a passport so it's sort of academic, but I'm not sure if I could lay my hands on my birth certificate. I'd certainly have to look through some file cabinets to see if I could find it and who knows if it's an original or not.

For people without a passport, it's extremely easy to have lost a birth certificate at some point over the years. And I honestly have no idea how easy or hard getting a new one issued is from some potentially far away city or town.