Hello all. I'm fairly experienced in grannyology as I like to call it and if anyone needs any pointers, I'm happy to help. Personally, I start from a position of disbelief and work towards closure as any and all records that involve people can be erroneous. I often use the rather cracking but not unusual example of my CousinHusband's* great grandmother. Her birth certificate has no father listed, however, when she comes round to getting married, one William Jefferis, a butcher, deceased is listed as her father. He's not her father at all, he's her grandfather. We don't know why she did this, she may have not wanted to admit she was illegitimate, she may have been told that William was her father, they are all dead and we can't ask them. What is important to note though is that 'official' record or not, her marriage certificate is incorrect - and this is why I start out with the question in my head of 'convince me this is right'.
*Nothing like grannyology when you find out your husband, who you didn't even meet until you were 39, and yourself have the same set of 8th great grandparents.......