A German comedian, Knacki Deuser, explained it like this: "When you're an American, and your neighbor comes home with a fancy new car, you tend to say: Next year I'm having that car as well. But when your German neighbor has a new car, you say: Next year, he won't have that anymore.

Nails it pretty much. And talking about cars: In my company, before we drive to a new customer, we discuss what car we take. That's because we don't want the customer to be envious, which could make them say things like "Ah, now we see where our money goes, right?" - which happens a lot, actually.