Quote Originally Posted by Kagemusha View Post
No its not.In majority of cultures including European becoming of age for males has been around 15-16 years, 21 is isolated occurance and to be honest very strange. If you can go to war, vote and drive a automobile, why cant you drink alcohol or go to clubs?
Yes it is, a very good reason - it has to do with wearing heavy armour.

21 is the historic age of majority in much of Europe because it was the age at which you could fight in war in your own right, instead of by proxy.