names.

if one grew up respecting somebody as an elder and a teacher, but, once you've grown up and are no longer being taught by this person and have become friends, how does one know when to stop calling this person 'mr. whoever' or 'coach whoever' and call them by their name. i mean, occasionaly you may have called this person by their first name, and it was no big deal, but most of the time they were mister or coach....how does one know when its time to ditch those formalities?

its odd