A year after he died, I learned that my father had a different name for part of his life. Since then I’ve learned he had a different nationality, too. I’m endlessly fascinated and once again am in a research stage. Today, a cousin (second cousin? cousin once removed?) wondered why my father served in the Royal Danish Navy when he was 26 rather than when he was 18-ish.

My dad was born in 1912. He always said 1913, but the Norwegian Navy said 1912, and when I tracked down his birth certificate a handful of years ago, it said 1912. In 1933, he went on the 7th Thule Expedition to Greenland with Danish explorer Knud Rasmussen. The expedition, using an airplane on a wooden ship, charted the eastern shore.

After my father died, I learned that he changed his identity in the late 1930s, at least partially because his name "sounded too Jewish."

He rarely spoke about the war or the time before. My dad was extremely private, and I never dared ask. I wouldn’t have known what to ask, anyway. The few times he mentioned something, I became still, almost holding my breath.