Joanne described her childhood as unhappy and complicated. Her mother was stricken with multiple sclerosis and her relationship with her father was estranged. Yet, she found occasional joy in composing fantasy stories, and reading them to her sister.

After finishing school, Jo took a job as a researcher and secretary. One day, while riding a commuter train to work, there was a long delay. She was late, and everyone around her was growing exasperated.

While staring out the window, an idea for a new fantasy story began bubbling up in Jo's mind. It was about a boy with magical powers. She began scribbling the plot points on napkins, and when the train finally started inching along--nearly four hours after stopping--she had assembled a rough idea for the beginning, middle and end of her new story.

Jo was only able to work on her story sporadically between odd jobs and caring for her mother, and she stopped writing altogether when her mother died a few months later. She eventually got married, moved away, and had a child.

After two years, Jo's life began to crumble. She was involved in a messy divorced, she grappled with clinical depression, and she was haunted by suicidal thoughts--all the while, she struggled financially to support herself and her daughter.

Jo eventually completed her manuscript, nearly five years after first conceiving the idea on the delayed train. At this point, she and her daughter had been surviving on welfare.

Her rewrites included themes about the hardships she had personally experienced over the years: the death of a parent, depression, and poverty. To her dismay, the manuscript was roundly rejected by all 12 of the publishers she submitted it to.

However, a year later, she received a meager advance from a smaller publisher, only because the publisher's 8-year-old daughter read the first chapter of her book, and wanted more.

In an effort to appeal to young boys, the publisher requested that Joanne use a more masculine name. So she adopted the initials for her first name, and her grandmother's name, Kathleen.

Jo's fantasy book eventually became a bestseller, and she went from living on welfare to becoming the first writer in history to earn a billion dollars from writing books.

And to think, without her train being delayed for four hours, J.K. Rowling might never have conceived of the idea to write one of the most famous books of our time: Harry Potter and the Philosopher's Stone.