Very early in my family history research.
As an only child, parents deceased, but memories of two grandmothers.
What I thought I knew was soon dispelled from records, that proved differently and then the whole family tree developed through validated sources back to 16th Century.
In essence, I moved around the UK before settling in Harrogate, Yorkshire, 25 years before I retired to Spain, where I decided to investigate the family, through the Internet. I believed my family were from County Durham, were I was born.
No, in part my father's side from Norfolk but more than 75% of the whole family were from Yorkshire, indeed all within a 30 mile radius of Harrogate.
Sources & records revealed all this, but my largest surprise was sourcing the burial of my "x" great grandparents more than 200 years ago, in my Parish Church in Harrogate, 800 m of where I lived.!
My belief, "don't guess" rather "prove"!