Writer Sebastian Sim has held an eclectic range of jobs, including bartender, McDonald's restaurant manager, checkpoint security officer and casino croupier.

At the age of 50, he has published his first English-language novel, Let's Give It Up For Gimme Lao!, more than three decades after the writing bug bit him.

Fittingly, the book, which chronicles the life of its titular character, is an accumulation of his life and working experiences.

"I wanted to capture Singapore's changes over the past decades. Gimme Lao shares the first half of my story, then he goes to university.

"I chose not to go down that path, but I let him go down that route, to subscribe to the mainstream values of having a career, money and a family, as I wanted to see where it would lead him. Would he be happy?" he tells The Sunday Times.

In the book, Gimme Lao seems to live the Singaporean Dream - he scores good grades, enters medical school, raises a family and is promoted to hospital department head.

However, his life is marred by quiet tragedies - his parents are constantly at odds with each other, he is misled into a shotgun marriage by his wife, who lies about her chequered past, and his son comes out as a gay man just as he is about to run for political office.

Sim adds: "Most of us would see him as a success story. But I feel like he misses out on a lot of things. Lao uses external factors such as his career and title to define himself. He doesn't invest in genuine relationships."

Let's Give It Up For Gimme Lao! was among the four finalists for the inaugural Epigram Books Fiction Prize last year, but lost to O Thiam Chin's Now That It's Over, to be released next month.

The $20,000 prize, started by publisher Epigram Books for unpublished novels in English written by Singapore citizens, permanent residents and Singapore- born writers, is the country's richest literary award.

Sim's life could not have panned out more differently compared with his protagonist.

Raised by Chinese-educated insurance agent parents, he grew up in a two-room HDB flat in Taman Ho Swee.

He attended River Valley High School and, later, Hwa Chong Junior College.

After his national service, Sim gave up a spot at the faculty of arts and social sciences at the National University of Singapore and went to New York City, lured by the bright lights of Manhattan.

There, he spent a month knocking on publishers' doors to pitch his first manuscript, a horror story he had toiled away at while in the army.

He recalls: "When I was in the jungle, I'd think of story ideas. I snuck a typewriter into camp so I could work on it after hours when my friends were playing carrom or sleeping."

Those publishers' doors slammed in his face repeatedly, as they told him that they represented only established authors. He eventually gave up, tossing out the manuscript.

But the experience ignited a yen for travel in him. Over the next decade, he travelled to countries such as India, Pakistan and Turkey, trekking through the mountains there. "I'd work in a job for one or two years, save up money to go off, then come back and do it again," he says.

During those itinerant years, Sim, a bachelor, kept writing.

When he turned 30, Sim took a "more stable" job to concentrate on writing - supervising drug traffickers and secret society members at a maximum-security prison.

He says: "I had no degree, so I had to do something on the ground. But my shifts were regular, so I could commit to writing. I'd have an early dinner, sleep at 9.30pm, wake up at 3.30am, drink a can of Red Bull, write till the morning, shower and report for work.

"I had to motivate myself to keep writing, but it was easy as writing anchors me and gives me a sense of purpose. If I don't do it for a while, I will itch."

Sim, who is bilingual, switched to writing in Chinese as he realised his attempts at writing an English book were going nowhere.

In 2004, he published his first Chinese martial arts novel series, The Heavenly Chef - about a talented cook who joins the pugilistic world - with Lingzi Media.

He followed up with a spin-off, Tears Of The Bat (2006). Both series sold about 900 sets in total.

He suffered from burnout in 2007 after releasing the two series, so he took a break from writing for two years while working at a security company.

"During that time, I read and caught up on things I didn't have time for when I was writing," he says.

His Chinese novels were written under a pseudonym - Yue Guan Ming. The pen name is a tribute to his father who died of heart failure when he was 17.

His mother, in her 70s, is retired. He has a younger brother, in his mid-40s, who works in the IT industry.

Sim says his love of the written word was sparked by jaunts to the library as a child.

"My parents would drop me off for an hour there and I'd read everything from Enid Blyton to detective to horror stories," recalls Sim, whose favourite books range from American writer John Irving's The World According To Garp to Chinese author Cao Xueqin's literary classic A Dream Of Red Mansions.

He learnt the magic of storytelling from a primary school teacher, who would often set aside five minutes in class to narrate fables and stories.

"You have to engage your readers, capture them and hook them for the next instalment. Every five or six pages, there should be a hook to feed the reader," he says.

Sim holds a day job in event management, but continues to write in his free time.

He was about to complete Gimme Lao when a friend told him about the Epigram Books Fiction Prize last year, so he submitted the manuscript.

He says: "I'd have looked for a publisher to publish my book anyway. I'm relieved that I didn't win as there'd be a lot of expectations.

"Keeping a lower profile as a shortlisted author who didn't win gives me more time to work on my next project."