Actually this is true (and proves that I am at least partly human) - the one grandfather who died before I was born (and whose first name is also mine, even though he preferred to go by the shortened form of his middle name, Gus) was a storyteller in every sense of the word. He could gather and work crowds without even trying, and told some stories that, when his older sister realized he believed them, she gave dad the joke book their father got them from; most of the jokes were about three or four lines and his stories took minutes to tell so he embellished a LOT.
The one that made my aunt break dad's illusion that his father told real stories was this:
"The fire that killed my birth parents also destroyed the local church. Most of the community donated what they could to create a comfortable place of worship until they could collect enough donations to rebuild [here he named which family offered up space, which one provided a piano as nobody owned an organ, etc.]. Only the local pharmacist held out, but just before they were to hold their Christmas Eve service, he turned up with two crates of hymnals - more than enough for the congregation.
"Everyone gathered around, and as the service opened, they all turned to [specific hymn number]
"Hark the Herald Angels Sing/Fix Some Pills, They're Just the Thing/Two for Man and One for Child/God and Sinners Reconciled."
Except for the local names, and him using a real incident (the fire that made him an orphan) instead of a particularly nasty snowstorm destroying the church, this joke was verbatim in the book she showed him.