From Live Science:
There may be a reason grandparents repeat the same stories over and over again. According to a new study, older people are more likely than younger people to forget with whom they've shared information.
The study investigated two types of memory: source memory, or your recollection of who told you a piece of information; and destination memory, which is your recollection of which people you've informed. Not only were older people bad at remembering to whom they'd told information, they were very confident in their mistaken memories. [10 Ways to Keep Your Mind Sharp]
Read more ....
My Comment: I am repeating stories .... and I am 50. Oh .... oh ....