What do we learn in this first part about Germany before World War 2?

In this section, we learn that Max's father Erik and Hans fought together in WWI. We also learn that the fact Erik saved his life changed Hans forever. Hans didn't join the NSDAP like so many other Germans in 1933 for this reason. Persecution against the Jews had already begun, and Hans refused to be a part of it. None-the-less, over time, he found himself in the position of having to do something he didn't agree with because neighbors (German neighbors) started to sit in judgement of each other. Hans applied to join the party in addition to helping Jewish neighbors. He was ostracized for his efforts on both sides. Hans was placed on the waiting list for Party membership because his actions were considered suspicious and sympathetic. Life in Germany was changing faster than its citizens could keep up with.