That is indeed interesting. I live in Germany, and it is sometimes very annoying that mostly, you can pay solely by cash (nur Bargeld! meaning only cash, is a common note at many counters). Go to even big celebrations like Volksfest, Oktoberfest, or Christkindlmärkte, you better have cash at hand. God forbid if you get stuck at a village without the precious Bargeld, the anxiety you get searching for an ATM is very real. But, now that you mention it, it makes sense that the Germans are known to be big savers. I wonder if it is a correlation or causality though...