Author JK Rowling has said the enormous wealth the Harry Potter books have brought her made her feel guilty.
Rowling said she cried after killing a character
In an interview with Newsnight presenter Jeremy Paxman, screened on BBC Two on Thursday, she said the rewards had been "completely disproportionate".
The Sunday Times estimated the writer's personal wealth was £280m, making her richer than the Queen, but Rowling denied that was the amount.
Whatever the actual figure, it is certain to grow following the release of her fifth novel, Harry Potter and the Order of the Phoenix on Saturday.
"The biggest jump for me was the American advance which was enough for me to buy a house, not outright, but you know we'd been renting until then," she told Paxman.
"And I didn't feel guilty, I felt scared at that point. Because I thought I mustn't blow this: I've got some money, I mustn't do anything stupid with it.
"And then yeah, yeah, I felt guilty. Yeah I did. I mean at least I could see cause and effect. I knew I had worked quite hard for quite a long time."
She explained that she now had no idea how much money she was earning.
"I met my accountant recently and I said 'They say in the rich list that I am richer than the Queen, so that means you've embezzled quite a lot of money'.
"I mean I do know what ball park I've got. I mean I'm not that clueless. And I certainly have not got £280m."
Rowling told Paxman that her success meant she did not feel like a "total waste of space anymore".
She said: "I was lousy. And now I feel that, it turns out there was one thing I was good at, and I'd always expected I could tell a story, and I suppose it's rather sad that I needed confirmation by being published."
In extracts released from the interview earlier in the week, Rowling said she had cried after writing the death of one of the Potter characters.
She also said she looked forward to a post-Harry era in her life.