It shoulda been clear he was nuts right around the time he grabbed Czechoslovakia.
If he had stopped with the Anschluß Österreichs he’d have as many libraries and streets named after him in Germany as MLK does here.
The lesson here is when a leader who does a few things you like
promises to do other things you don’t like as much best take them at their word.
Aside from his being a racist murdering jerk he was not that bright.
But neither were the people following him.
But basically Hitler wanted all the lands of the former Austria-Hungary under German control, or at least in their sphere of influence, the idea of Czechoslovakia being allied with Britain and France meant basically they would have Germany surrounded.