@evan True. Context is my dad was born in Belfast and immigrated to USA at age 18. He ended up naturalizing while in the Marines. As part of that process, he seemingly “gave up” his UK citizenship. But there doesn’t appear to be a UK law that allows for that. So I derived UK citizenship upon birth, we just didn’t know it (or so is our understanding, we haven’t filed paperwork yet). Because he was born on the isle of Ireland, I can derive Irish citizenship too.