That time my grandfather invented the Frisbee

Grandparents always have stories. When we hear them, they are endearing, and we weigh the fact vs. make-believe quality of them. 
My grandfather has always talked about how he and his siblings invented the Frisbee. The way his story goes, there was a pie company in the neighborhood that would sometimes leave empty pie tins around. He and his siblings would take the tins and toss them back and forth to each other as a game. 
One day I decided to do a Google search on the origins of the Frisbee. Wikipedia says: 

The Frisbie Pie Company was founded in 1871 by William Russell Frisbie in Bridgeport, Connecticut, when he bought and renamed a branch of the Olds Baking Company. The company was located on Kossuth Street in Bridgeport's East Side, where nearby schoolchildren tossed the plates around and yelled "Frisbie" so they wouldn't get hit by the spinning tins. The game the children played made its way to nearby college campuses.

So I read that and I'm like: My grandfather and his siblings grew up in Bridgeport, Connecticut... near Kossuth Street... on the East End... and they were school children.
So I am now completely convinced that my grandfather and his siblings did indeed invent the Frisbie. 
What's one of your favorite grandparent/parent stories?