Oh, agreed. I look back (from the lofty heights of 28) on 15-year-old me thinking that 18 was totally adult enough for superpowers and the fate of the world; or, better yet, 12-year-old me thinking the same of 15! Yikes.
And the enthusiasm of some of those wise mentors for sending actual minors off to find the great evil ravaging the land with nothing more than a magic sword and some advice which, I suspect, they cribbed from a fortune cookie... double yikes.