Quote Originally Posted by rajpoot View Post
Why do you think that a person had to be 21 to wear full plate?!
Granted that some of the suits were prohibitively heavy, but a tough 16-17 year old can carry as much weight as any man.
Furthermore on average full plate suits weighed between 15-25 kgs. Which isn't all that heavy if it's distributed all over your body.
Oh no, it was much heavier than that: http://www.bbc.co.uk/news/uk-england-leeds-14203621

You start at 7, and after 14 years you have sufficient condition to fight in the stuff for extended periods. A "tough 16-17 year old" cannot carry as much as a soldier for as long - you only have to look at the soldiers in modern armies, the 18 year old infantrymen are noticably smaller than their NCO's, especially accross the shoulders. It's worth noting that pretty much no one today can fight in full plate effectively for more than about 10-20 minutes tops before they are exhausted, just like there is no Englishman alive able to draw a fullsize warbow.