Max Vandenburg, from Markus Zusak's The Book Thief, is not a naive character. (Naive means that one does not possess experience, wisdom, or solid judgment (based upon prior experience).) Instead, Max proves to be rather knowledgeable about the world.
Max proves his lack of nativity by jumping from a train car headed for a concentration camp. Since he is aware of what is to come, Max proves his knowledge about what is to come by escaping. Max is determined to find out what happened to his family after leaving them to the S.S. A naive person would not consider what the fate of his or her family was. In fact, a truly naive person would not consider any wrong had been done at all.
Max hides for years from the Nazis and their seeking out of Jewish people and populations. His knowledge of the extermination of the Jewish people forces Max to seek protection for multiple years. Again, a naive person would fail to see any need to action.