The idea that German soldiers were all young men in their teens and early 20s is based more on an idealized caricature than historical reality. As the war dragged on, manpower shortages became so acute that many men previously passed over for medical reasons were called up to serve. The average age of the German Army in 1944 was 32; in Normandy, the average age in some gun crews was 45, some of the men were over 55. Of course, not all of these older fellows were assigned to combat duty. For every German soldier at the front, there were three in the rear, performing logistical or administrative tasks, on occupation duty, in training units, or home guard units, etc. As the front line came closer to Germany, many of these men found themselves in combat zones. I uploaded some scans of a Soldbuch I have for a 59-year-old draftee and WWI veteran who was assigned security duties in a Landesschützen unit. When he was released from the POW camp after the war he was judged to be malnourished, senile and unfit for any duty. A far cry from the supermen of wartime propaganda and post-war legend.