The 'Troublemaker' singer explained that the book details his life since appearing on The X Factor, rather than a full life story so far.
"It's interesting to write a book, I've been asked to do one for three years," he told BBC Breakfast.
"With the success I've had, it has been nice to explain it in my own words. It's not really an autobiography, it's the last five years. The first few were a bit boring!"
"It's about how The X Factor has changed my life," he explained, stating how he had been "lost" while working at a call centre before auditioning for the show in 2009.
> Olly Murs's new album Right Place Right Time: First listen
Murs also spoke about a "low point" last year, in which he became "depressed" following his appointment as Xtra Factor co-host, and a poor appearance on 8 Out of 10 Cats.
"At the end of last year, I was really anxious and felt under pressure, I'd just started Xtra Factor," he explained.
"I was very conscious because I had my album coming out as well. I was worried people would see me as presenter instead of a singer.
"My head was all over the place, I had a really low point. I felt like I lost my personality for a month, I was being grumpy and moody."
Olly Murs's book Happy Days is released in stores today (October 11).
New! Digital Spy breakfast show - watch Alex Fletcher discuss the day's biggest stories including the Rooneys' baby joy, Cheryl Cole's long-awaited autobiography, what's next on Doctor Who and more: