In both Maus I and Maus II, we see Vladek's struggles through the Holocaust, and his peculiar method of saving things that will help him later, and often these saved things (whether they be material or skills) save his life. In the present, however, Vladek's tendencies are irritating to his family and friends, and make him come across as extremely miserly. Do you think his hoarding tendencies are a result of the Holocaust and his experiences in it, or were they always present?
On a related note, one thing that Vladek does not have left over from his days in the Holocaust are Anja's diaries, which he claims he burned shortly after Anja's death. Although this certainly seems possible, given his trauma over the event, it's also entirely possible that they're simply hidden somewhere in the mess of his house, and he doesn't want to give them to Artie, given his love for Anja and his fondness for holding onto lost things. Which do you think is really the case?