How is Nechuma mistaken in her optimism at the start of the war in the novel, We Were the Lucky Ones?

Nechuma recalls the deprivation and persecution she suffered during World War I and believes that surely conditions will not devolve to that level again, but she is woefully mistaken. Nechuma and Sol are forced from their home and into a ghetto by the Nazis. When it becomes apparent that the ghettos are being dissolved and the inhabitants sent to death camps, Halina rescues her parents and leaves them in a safe house in the country near Radom. Halina returns to collect her parents in Chapter 53 as the war is coming to an end, and the Kurcs make their way to Rio to be reunited with Addy.