I have been into genealogy since about 1998 and if I could have a nickel for every mistake I have found, I would be wealthy. There are records out there that someone with a very good imagination put together. It is very easy to spot them if you do a little more research. Someone can start with someone famous and try to find some kind of link to their ancestors. It does not have to be real. The same thing is true of people trying to become members of the DAR. That is why they started requiring proof which I do not want to take the time to do. I know it and that is enough.
Yes, plenty of honest mistakes, and old family myths. Plenty of deliberate mistakes, too, handed down from earlier times.
Shakespeare’s father bought himself a coat of arms, after he had made some money. That was not uncommon among up-and-coming Brits in those days. The beer barons in the time of Queen Victoria are another famous instance.
Some members of my grandmother’s family have been members of the DAR since the fifties. We had pretty clear information about the service of two of the ancestors, less about others. We are even having trouble verifying some information from headstones.