The Italian premier's bizarre request at a No. 10 Downing Street dinner was among the "surreal" moments Sarah Brown recalled in an interview with the Daily Mail. "Harry Potter" author J.K. Rowling was also present, she said.
During her time hosting royalty, world leaders and celebrities, Sarah Brown said she was "star-struck" only once, when she met Barbra Streisand. George Clooney was a "brilliant operator" and networker, she said.
Brown's diaries begin appearing in the Daily Mail next week.
She said she regretted not speaking up more to defend her husband, who was voted out last year.
"When things were going wrong, and I was reading stories about him that simply were not true, I wonder whether I should have got more involved, to say: 'This is just not the case.' The one thing that I could have done to make a difference was to be more vocal," she said.