On a delayed train journey from Manchester to King's Cross station in London, the characters Harry Potter, Ronald Weasley, and Hermione Granger came "fully formed" to the mind of a young temp named Joanne Rowling.
In the six tumultuous years following, she would imagine an entire magical world of witches and wizards, assume the pen name J.K. Rowling, and publish "$4" the first novel in the now beloved "Harry Potter" series.
Rowling has since become the UK's best-selling living author and one of the $4, but not before overcoming the hardships of being a single mother living on welfare.
Born in the southwest of England, Rowling grew up along the border of England and Wales with her mother, father, and sister.
On her website $4 she would be a book author. "As soon as I knew what writers were, I wanted to be one. I've got the perfect temperament for a writer; perfectly happy alone in a room, making things up."
She wrote her first book (about a rabbit named Rabbit) at age six, and when her mother praised her work, she says she "stood there and thought, 'Well, get it published then.'"
She $4 as the day her mother died - it was New Year's Day in 1991 when Rowling was 25. This was six months after she began writing "Harry Potter," and she lamented that her mother never knew she was writing it. The loss of her own mother would eventually lead Rowling to make Harry Potter suffer the death of his parents.
"My books are largely about death," she told the Telegraph in 2006, referencing not only the death of Harry's parents, but also the villain Voldemort's obsession with immortality. "I so understand why Voldemort wants to conquer death. We're all frightened of it."
After her mother's death, Rowling moved to northern Portugal for a fresh start and taught English as a foreign language. She started dating a man named Jorge Arantes, became pregnant, and moved into a small two-bedroom apartment with Arantes' mother.
The couple miscarried, but they married in October 1992. Rowling later gave birth to a daughter, Jessica, in July 1993.
The rocky marriage lasted a mere 13 months, and Rowling and Jessica returned to the UK to live in Edinburgh, Scotland, not long after. She carried three chapters of "Harry Potter" in her suitcase with her.
Living in a cramped apartment with her daughter, jobless and penniless, $4. She was forced to rely on state benefits and spent much of her time writing "Harry Potter" in cafés with Jessica sleeping in the pram next to her.
"An exceptionally short-lived marriage had imploded, and I was jobless, a lone parent, and as poor as it is possible to be in modern Britain, without being homeless ... By every usual standard, $4," Rowling said during a 2008 $4.
According to the book "$4," three days after the Harry Potter book was published in the UK, Scholastic bid $100,000 for the American publishing rights, an unprecedented amount for a children's book at the time.
Her series of seven books has since sold more than 450 million copies, won innumerable awards, been made into movies, and transformed Rowling's life.
In 2011, Forbes estimated Rowling to be worth about $1 billion, but $4 after reportedly giving some of her wealth to charity. She remains on its lists of $4 and $4.
The very best thing her wealth has given her, she wrote on her website, is the absence of worry. "I have not forgotten what it feels like to worry whether you'll have enough money to pay the bills. Not to have to think about that anymore is the biggest luxury in the world."