Lewek and his five brothers and sisters were born to religious Jewish parents in the town of Kozienice, situated in east central Poland near a birch forest. Lewek's father owned a sawmill, and when Lewek and his brothers were grown, they helped their father manage the family business.

1933-39: When I was 15 I attended an agricultural school near Kozienice, because I wanted to emigrate to Palestine [Aliyah] to work the land. But after the Nazis rose to power in Germany in 1933, emigration preference to Palestine was given to Jewish youths from Germany. Seeing I had no chance to leave, I returned home to Kozienice, where I was trapped when the Germans invaded Poland in 1939.