Pope Benedict XVI was born on April 16, 1927. Do the simple math. He was a school boy during the war years.
There was no such thing as just a school boy in wartime Germany.
From 1936 onwards, every boy in the country was enrolled in the Hitler Youth. As the war situation worsened, the HJ were increasingly incorporated into the fighting apparatus of the country. In 1942, that meant 15 year old kids working the fire brigades after RAF bombing. In 1945, it meant 12 year olds being sent to Volkssturm units to fight Russians house to house in Berlin.