This word of mouth passing down of information is interesting.
My Great Grandfather died in 1938 aged 80. He received an obituary in the Tully on account of his death being unusual, having dropped dead "overcome by excitement" watching Lochee Harp. What intrigued me was the reference to having one arm.
He was originally a stonebreaker to trade so I assumed that he had lost an arm building railways or suchlike - the proverbial 19th century Irish navvie.
But no, just recently I came into contact with a nephew a couple of times removed who was able to confirm through an elderly relative, a great granddaughter of my Great grandfather that he had been born with one arm. This would have been in 1858.
This information would have been passed down through three generations simply by word of mouth.
He didn't do anything especially noteworthy in his life, but was remembered over 150 years after his birth.