From Der Spiegel's piece on the start of the WW1 Centennial year,
The survivors of World War I included Franz Warremann, a journeyman bricklayer from the northeastern German city of Rostock, whose grandson, Joachim Gauck, is Germany's president today. Warremann brought home a helmet from the front that had been dented when it was grazed by a bullet just above his left temple. He had apparently been extremely lucky.
The dented helmet has since been lost, says Gauck in his office at Bellevue Palace in Berlin, but the sight of it created such a strong impression on him that he could "still draw it" today.
When his grandfather got together with other veterans in the evening and they talked about the war, young Joachim was always surprised at how exuberant they seemed. How could they be so happy after those harrowing experiences?
Only much later did he understand that the men treasured spending time with fellow soldiers who had also looked death in the eye in the trenches. Only they could understand what it meant.
And that was why they were celebrating life.