Heart to Start - part memoir, part entrepreneurial field guide - sheds light on the unseen struggles before Handley's multi-million dollar sale of The Hyperfactory in 2009 and 2010.
It reveals flashes of self-doubt and anxiety that he "wasn't cut out to do this entrepreneur thing".
It exposes the poor decisions he made, the moments he regrets and the things that still make him cringe.
But more than any of this, it shows his grit when the wolf was at the door, and his belief that he could achieve what others saw as impossible.
"On paper our entire story was one word: impossible. In a business plan it would have been laughed out of every boardroom or business school," he wrote.
"Impossible. But it happened."
While much of Heart to Start treads over where Handley has been, it is also a story about where the now 35-year-old is yet to go.
Handley's narrative reveals that even when The Hyperfactory's sale was hanging in the balance, he knew the thrill of growing a business or chasing success would not be enough to satisfy him the next time around.
"If I died tomorrow and the world asked what Derek Handley had done with his time, would I love the answer? No. It was clear to me that I hadn't made an ounce of impact on the world at large," he wrote.
With an ambition to "become a new type of entrepreneur", to leave the world better off than when he arrived, Handley left the Hyperfactory to discover the problems facing his generation and a way to do something about them.
His search took him to Africa and the micro-financing of projects that gave farmers or traders the funds to do more than just live hand-to-mouth.
However, it wasn't in a poverty-stricken village where Handley would chart his next course, but at a luxury resort on Sir Richard Branson's Necker Island.
It was there, over a glass of wine, where Handley agreed to give away year of his life to work with Branson on a project that became known as The B Team.
The B Team is a initiative hoping to create a "brighter vision of capitalism", where businesses look at not only making a profit but also at solving environmental and social issues.
The project has yet to launch, and although Handley originally committed a year of his life to the pursuit, he said it would now be "foolish" to not see it through.
"I've only started to learn how little I know in this world and about this leading edge of what's really a movement. It would be foolish to step down now and do something else. I hope to stick around to see The B Team launch and get into the first real piece of work which will be out in the coming months," Handley told the Herald .
But along with The B Team's attempts to get business to shift focus, Handley says members of the public also have a part to play.
"The world needs more and more of a groundswell of the public to support this initiative, where it isn't good enough to work for companies who don't have some sort of social or climate mission. It as simple as where you work, all the way down to how you might spend your time or how you might spend a few dollars," he said.
But just where does his book fit in to all of this?
Handley sees Heart to Start as a story that people can "be inspired by or just think about" and one where readers can consider for themselves if they are "living the life they were put here to live."
"It's for anyone who wants to take a step back and think about the long term," he said.
While Handley says critics will think he hasn't experienced enough at his age to write a book, he believes there is value in what he's found out.
And he can recall at least one person - a 22-year-old that was $100,000 in debt 13-years-ago - who would have got a lot of out of it.
