Hermione Jean Granger was confused.
She had recently returned home from her sixth year at Hogwarts, Albus Dumbledore, headmaster and leader of the light, had been killed.
She knew it was only a matter of time before her parents were hunted down and slaughtered by Death Eaters due to her relationship with Harry Potter, the Boy-Who-Lived, and due to the fact that she was a muggleborn witch.
A smart muggleborn witch. Very smart.
Yet she was confused.
On the train ride home, as the rest of the Hogwarts students were dealing with the fact that the headmaster was killed and Death Eaters had terrorized the castle, Hermione was dealing with the fact that the only way she'd have any chance to protect her mother and father was if they had no idea who she was. The safest place she could put them was as far away from her as possible. She had to obliviate them.
So, as she got out of her parents car, after having arrived home from Kings Cross Station she followed them inside, sat them down, and made them tea. They asked her how her school year went. She said she had the highest marks of her year. They were proud. They were dentists, education had always been important.
She got up off the couch, with the pretence of running to the toilet. She stood behind her parents on the couch, watching the television advertise cheap flights to Australia. Hermione reached for her wand in her pocket, and quietly but clearly spoke "obliviate."
She picked through each and every memory they had of her and pulled them out of their heads. She found the summers and holidays spent with them during her breaks from her schooling. Letters she had sent telling them of her classes. Their trip to Diagon Alley before her second year. Meeting Professor McGonagall as she explained that she was a witch. She found the years she spent with them prior to learning she was a witch. She pulled everything out. Younger and younger she got in their memories. Five years old, getting storybooks for her birthday. Just over a year old learning how to walk and talk.
She reached all the way to her birth, her mother finding out she was pregnant after years of trying. Their miracle baby, as they always told her. Yet there was nothing there. Absolutely nothing.
There was no pregnancy. Her mother was never pregnant with her. Yet they had always told her of the morning sickness that seemed to plague her mother for the entirety of the pregnancy. It looked to Hermione that one day she had just arrived. One day she appeared in their lives, a bundle of joy, with the name Hermione. She could tell that it was important to them. That Hermione had to be her name.
To Hermione it reeked of magic. Someone had obliviated them and gave them a child that they thought was theirs. With false memories of morning sickness and the importance of the name Hermione.
She was confused. Who had left her with them?
She walked to her room, packed up her belongings that she had left behind into her Hogwarts trunk. She could hear her mother and father talking about how great an idea it was to move to Australia and re-start their dental practice there. She stepped out the back door as they were huddled around her father's computer buying plane tickets to Australia.
She quickly walked through her backyard, trunk shrunken and stuffed in her pocket, beaded bag slung around her chest, thought of The Burrow, and disapparated with a crack.