Stereotyping people and nations can be a dangerous but funny pastime, and the Germans have certainly had their fair or unfair share of it over the years, mostly being characterized as quite dry and humourless about things.
Good to report that that image is alive and well after two police officers in Berlin used pepper spay against against a crowd of youths who had been pelting them with snowballs, and then went on to arrest them all !
Easy to lose your sense of humour, more difficult if you don't have one in the first place