The praise from a German friend was the first sign that I had gone native.

“You see?” he said to his American wife, pointing to the sink where, without thinking, I was rinsing out the plastic yogurt cup I’d just emptied, unwrapping its cardboard sleeve and separating the foil from the lip of the container. “That is how to recycle!”

What may sound like a lot of extra fuss over trash has become second nature among Germans, the world’s recycling champions.