Everyone was pretty sure what the Nazis were going to do. It wasn't as much of a shock as we think today. Perhaps we could draw parallels to today.
Not really. Before 1939 Hitler was admired everywhere (including USA - he was made the Man of the Year by the Time Magazine TWICE!) as a great leaders who saved his nation from Great Depression and from humilation.
The problem is that people who want to avoid the fate of Chamberlain invent the "second Hitlers" like Milosevic and help really bad guys (like Islamists invading Balkans).
The next Hitler will come the most unexpected direction. The history does not follow predicable Hollywood scripts and Hollywood movies are the main source of popular historical insight. Few people read Aristotle or Machiavelli, almost nobody reads Thucydides or Simone Weil.