My mother was born in March of 1923 so she died just shortly before her 89th birthday.
My mother imagines the occasion thusly: the country doctor who attended her home birth must have asked her father: "what are you going to call this little girl" and her father responded "we're going to call her Josie T." So the little baby girl who was suppose to be named Johanna Theresa after her grandmother ended up with a birth certificate that said her name was "Josie T."
She did not discover this fact for more than fifty years until she needed her birth certificate to get a passport. In her childhood she had indeed been called Josie T by her parents, brothers, Aunts and Uncles and cousins. But she was also often told that she'd been named for her grandmother Johanna. At college, the name she earned her certificate under was Johanna Theresa. The social security number she got before her first job was assigned to Johanna Theresa. When she married, the name on the wedding license and register was Johanna Theresa. Her children's birth certificates named their mother as Johanna. On the title to the house she'd signed Johanna.
In the 1970's when my father retired and my parents decided to do some world traveling. Mom wrote away for her birth certificate. When it arrived and she eagerly opened the envelop her first reaction was shock. Then she was angry. I think that was the most pissed off I had ever seen my mother up to that point in my life. She stormed around the house cussing at her father. She said to me that she just knew how it happened. She had this image of her dad had been joking and talking with the doctor, and when the doctor said "what are you going to call her?" he just didn't think, and told the doctor what they were going to "call" her, not what they were going to name her.
As the shock wore off, the disorientation set in. She began to wonder if everything in her life was a lie. Did she really have a teaching certificate? Was she really married? Were we really her children? Did she own the house? It was a disturbing thought. If she'd done all these things as Johanna, and she wasn't really Johanna, then had she done any of them?
The question arose - what would she do about her passport? She decided that she'd be damned if she'd travel around the world with a passport under the name Josie T. For Pete's sake she didn't even have a proper middle name, just an initial. So she did her research, consulted a lawyer and went to court, and had her name legally changed to the name she'd used all those years, so that she could have a passport that said Johanna.