While there are plenty of people who say they are fed up with Prince Harry making headlines, it seems that far more people want to hear his story from his own perspective.

Exhibit A: His memoir, Spare, appears to have sold more copies on its first day of release in the UK than any other non-fiction book to date. It was released worldwide on January 10.

British royalty reporter Omid Scobie tweeted, "And there you have it! According to a spokesperson for Transworld Books (@TransworldBooks), the UK arm of Penguin Random House, Prince Harry's #Spare has become the fastest-selling non-fiction title in the UK. So far, it has sold 400,000 copies in all formats."

Larry Finlay, managing director of Transworld, said in a statement, "We always knew the book would fly, but it has exceeded even our most bullish expectations."

"As far as we know, the only book that has sold more in its first day is another Harry [Potter] book starring him" (via Reuters).

Meanwhile, according to CBS News, the memoir has been equally successful in the U.S., topping Amazon's nonfiction bestseller list and Barnes & Noble's Top 100. The New York Times bestseller list, however, was published before Spare's publication date.

In Spare, Prince Harry makes shocking and unexpected revelations about his life as royalty and his departure from the UK. For example, his experimentation with drugs, how he lost his virginity, and his complicated relationship with his brother Prince William.

"Spare" is available now and can be purchased at major bookstores.