Zajonc, born in Łódź, Poland on November 23, 1923, was the only child of the family. In 1939, before the Nazi invasion of Poland reached Łódź, his family fled to Warsaw. During their short stay, the building they were living in was hit by an air raid. Both of Zajonc's parents were killed, and he was seriously injured. The rest of his time in Warsaw was dedicated to studying at an underground university in Warsaw until he was sent to a German labor camp. He escaped from the work camp, got recaptured, and then sent to a political prison in France. After escaping for the second time, he joined the French Resistance, continuing his studies at the University of Paris. In 1944, he moved to England where he became a translator for the American forces during their European Campaign.
