Re: DTI: Forgotten History by C. L. Bennett Review Thread (Spoilers!)
Or to put it another way... without independent evidence, anything which predates anyone you've talked to (like your grandparents) could be very old or fairly new when they first heard about it. And that assumes their recollections are accurate.
"Some days are better than others. They say that where I come from."
"Loudly, I imagine, on the day you left."
(Blake's 7 - Rumours of Death)