Rene, his twin sister, Renate, and their German-Jewish parents lived in Prague. Shortly before the twins were born, Rene's parents had fled Dresden, Germany, to escape the Nazi government's policies against Jews. Before leaving Germany to live in Czechoslovakia, Rene's father, Herbert, had worked in the import-export business. His mother, Ita, was an accountant.

1933-39: Our family lived in a six-story apartment building along the #22 trolley line in Prague. A long, steep flight of stairs led up to our apartment, where my sister, Renate, and I shared a crib in our parents' bedroom; a terrace overlooked the yard outside. Renate and I wore matching outfits and were always well-dressed. Our days were often spent playing in a nearby park. In March 1939 the German army occupied Prague.