Are you officially a “senior” when your first issue of the AARP Bulletin arrives in the mail? Or do you become a senior when you earn your first senior discount at a movie theater or restaurant? And, while we’re at it, when does old age really begin? For the answers, check out my “Life Lines” column in the June issue of Michigan Prime, delivered this weekend with your Sunday Detroit Free Press. Or flip to page 5 to read it online.