As can be seen from the last seconds of this clip
http://search.eb.com/normandy/video/onormay151v1.mov
the 2cm flak helpers aren't much over 16 (are they 12th HJ SS?), but still make utterly dedicated fighters. Hitler taking over the education system in 1933 meant that 1943-45 he was just in time to be able to utilise youths who had been suckled on nothing else but his poison milk.