Entire German armies started surrendering before the German high command officially surrendered. It was different from most contemporary wars in that all sides were functional nation-states, with organized leadership, where the army generally was obedient to the upper leadership. When the leadership surrendered, the military stood down.

And no, despite that, it wasn't all that clean. Some German army divisions refused to surrender until early May 1945. There was sporadic resistance in the hills of Austria and in Yugoslavia until the end of May. In the East, Japanese holdouts, mostly in rural regions of the Philippines, Indonesia, etc., at the company level (dozens to hundreds of men) resisted in local pockets right into the 1950s, with the last guy not surrendering until 1974: https://en.wikipedia.org/wiki/Teruo_Nakamura

Psychologically speaking, both with Hitler's suicide and the Japanese emperor's announcement of surrender, people who lived through it often spoke of it like a spell being suddenly broken, all fervour evaporating in an instant, with intense tiredness and emptiness replacing it. They also spoke of relief. The leadership of the Axis had sworn that everyone would die to the last man if need be. And they had fought on long after the war was obviously lost. The surrender suddenly presented the possibility that people might just live. The fact that the Axis populations were starving and that the Americans started shipping in food, probably also helped convince people that it was better to not resist.

It's also hard to overstate the absolute scale of the purely military aspect of the victory and the occupation of the Axis territories. Nearly all infrastructure and military hardware had been destroyed. There were around 10 million Allied soldiers in Germany in April 1945 -- a ratio of about 1 occupying soldier to 7 German civilians. Meaningful and organized resistance seems impossible in the face of that. And the occupation troops did not leave until the Allies set up puppet governments that could and would crack down on any resistance to the new order.

Thanks very much, fascinating.