Any Thoughts Why Germany Was So Prepared for WWII?

Primarily because they had been planning the invasion for more than a decade, while the allies naively believed that the war would never happen. They were also the first to put air support control with field units via radio's most other Armies at the time retained control with a higher command causing tactical delay. (Napoleon was the first to use a cannon in combined arms, Hitler used tanks and airplanes) But the primary reason wasn't that Germany was so prepared it's that the French reliance on the Maginot line and the Dyle plan fell right into Germany's Plan resulting in Dunkirk. https://en.wikipedia.org/wiki/Dyle_Plan

The German education model for their staff officers and junior leaders was excellent. Ironically (considering how Nazis took power), staff officers were taught to be critical thinkers and they analyzed the lessons of not only from WW1 but conflicts before that and determined why things happened the way they did and worked on solutions to not have it happen again.

It has to do with the way of thought during this time. They adjusted to the changes in warfare where the west did not.