First let me say, I know the game does not have any component that equates to an age of a character 
. I just was thinking that if all my characters started adventuring around the same age then hold old would they be at the currenty level of development.
My idea uses the base age of 15 (squire, student mage, young adventurer) who has set out to find his/her own life. Since the only tool for aging is the character's leveling then this will be component, but not a straight forward 1yr for every level. A 80 character would end up being 95 yr old 
.
So, for every two levels the character would be considered to be one year older, which means the 80 character would be a mature 55 years old and considered a master in their field. I don't use the tradeskill for aging since a person could always be more advanced/or less advanced than their age suggests (not all warriors are good at making weapons or armour or mages good at making spells and potions.)
But this is getting off track...
So between level 1 to 10 then the character is living his/her teens, learning the ropes as they say, at the ages of 15-19 years old. At the age of 20 years old when the characters, after making Lvl 10, is ready to take on the world as a young adventurer in EQ land (especially since this is when the game goes "no holds-barred on the characters and the player get to learn the hard way about using the adventurer skills.)
As I said, this is just a simple RP think piece that gives my characters some reality and does not represent any real rule for character development;
My senior character is a 60 Guardian which makes him 45 years old
My next favorite character is the adopted brother, a 41 Paladin - 35 years old
The Guardian has a younger brother, 30 Paladin - 30 years old
The distant cousin to the adopted brother, Paladin, and family friend is a 26 Ranger - 28 years old
And the old Guardian is robbing the cradle with a 21 Fury (female) - 25 years old (he may be old but he still gots the moves... every story has to have a love interest... right!!!)
The age of the character is really up to the player, but this is my way of saying, "That young punk (Lvl 20 something) whatever is still wet behind the ears and could learn a thing or two from this experienced (Lvl 55+) blowhard." 
Enjoy the idea and nit-pick it to your delight...