I know its old because my grandma gave it to me.....She was really old and she died 10 years ago. We have this statement made to us at every appraisal show that we do. It is usually brought on because of my telling someone that the item that they brought in for the appraisal isn't as old as they think it is. They typically get indignant because of my lack of knowledge and then proceed to blurt out the line "Grandma gave it to me...AND SHE WAS REALLY OLD!!".
Grandma's shop at Walmart too! We are grandparents, and not everything that we own is old. Grandma's everywhere on a regular basis put on their best pill box hat (complete with babies breath and white webbing), hop into their gold Buick LeSabre and head directly to the local WalMart. Why? Because Grandma's like nice things too! Not everything that Grandma owned was old, so be careful whenever you are using this overworked term.