STOCKHOLM, Sweden (JTA)—My childhood was full of magical, well-known tales about characters like Tevye the Milkman, as well as tales of love and joy and everyday life in the shtetls of Poland, told with warmth and wit by my grandparents.

There were Moyshe and Sorale and Feygele from the shtetl of Zamosc; people I never met but who were brought to life through my grandparents’ stories. Some of them became my childhood heroes.

As a little boy yet unaware of Auschwitz, I wondered about my grandmother’s sadness: Even when telling funny stories, she seemed to laugh with one eye and cry with the other. I don’t remember when I found out that all the characters, so alive in these vivid stories, were murdered in Auschwitz.

Properties seized by the Nazis and nationalized by the Polish Communist government after World War II is their only legacy....