My grandmother was never told who her parents were and was brought up by her 'grandparents' and 'aunts'.
She tried a few years before she died, to get a birth certificate, and was told that she was not registered at the then St Catherines House, and the church which was on her christening certificate had had a bad fire in 1970, so she just left it, thinking she wouldn't find out.
Then, my cousin from my dads side of the family started doing that side of the family tree, and that gave me the urge to start my mums side of the family's history.
Rebecca