In the US - at least in New York - there's a custom called a "doggie bag": When people are at a restaurant, and there's too much food, and they want to take some home, they ask for the waiter to wrap it up for them. This is quite common. That's often referred to as a doggie bag, under the fiction that "this is not for me, no, I'm taking it home for my doggie". See
http://en.wikipedia.org/wiki/Leftovers .
A friend of mine from New York was in Berlin, having dinner in a restaurant with a friend-of-a-friend, a Berliner, a retired banker originally from Municy. My friend said to the waiter, "I'm finished, this is too much food, can I take it home?" And the friend-of-the-friend said, no, I won't hear of it, that's impossible.
My question: Was this simply a personal objection of this friend-of-a-friend? Or is it not customary in Germany to take food home from restaurants?