I'm not sure on a bunch of Guardian stuff.

How old are Guardians?  Does Guardians age vary?

Can Guardians come from distant lands far from the chosen one(s) birthplace?

Do we make up a reason for how our Guardians know that they are guardians, or is there some kind of official calling for all of them to know that they are indeed Guardians?  

Would the Guardians know of each other like close friends or could they be practically strangers that just happen to have the same 'job'?