The 52-year-old "X Factor" judge, who launched the book at the Serpentine Gallery in London, said he was embarrassed and spent last week hiding under a pillow as extracts from the book were published, reported Contactmusic.
"I spent the week hiding under a pillow and I couldn't bear to look at the newspaper. I knew it was bad because friends were sending me sweet messages saying, 'Are you OK?'," he said.
The book throws light on how he wanted to sack singer Gary Barlow from the show for being too scripted, and how he deemed his ill-fated engagement to make-up artist Mezghan Hussainy to be a big mistake.
Cowell also said he had no idea what would be included in the final copy. PTI CORR NDS