JK Rowling's first fan letter was addressed to her as a man, after her first book in the Harry Potter series appeared.The author had been advised by publishers to hide the fact that she was a woman.

WhatCulture.com have assembled a list of ten things which we are assured we do not know about the Harry Potter author, JK Rowling, including the above startling fact. However, given the amount of interest which her books have garnered around the globe, in myriad languages and editions, there are surely thousands of readers who know, not just the ten things about Rowling outlined in the article in question, but 1,000 things or more.

Yet the little list does throw up some interesting nuggets like that she was advised by publishers to hide that she was a woman, hence the rather reticent pair of initials employed ever since, to devastatingly useful effect obviously. 

Her characters, The Dementors, were inspired by early depression, after the break-up of a short-lived marriage. She was in her early twenties, trying to raise her young daughter on her own. “My depression was characterized by a numbness, a coldness and an inability to believe you will feel happy again, " she declared. "All the colour drained out of life.”

We also learn that the author invented Quidditch after a row with her boyfriend. “Quidditch was invented in a small hotel in Manchester after a row with my then boyfriend, " she wrote in a book penned for a charity auction.

"I had been pondering the things that hold a society together, cause it to congregate and signify its particular character and knew I needed a sport. It infuriates men…which is quite satisfying given my state of mind when I invented it.”

The mega-popular novelist is no longer a billionaire because she has given such significant earnings to charity. “You have a moral responsibility when you’ve been given far more than you need, to do wise things with it and give intelligently.”

The late Michael Jackson wanted to devise a musical based on Harry Potter, but Rowling had no interest. “I said no to a lot of things, " she once told Oprah. "For me, I love the films, I love the books, and there’s elements that I love around it… like the theme park. But I only wanted to do it because I knew it would be incredible.”