So how have Hong Kong students who achieved 10 As in the Hong Kong Certificate of Education Examination (replaced in 2012 by the Diploma of Secondary Education) fared as adults? We meet four top performers who finished Form Five about a decade ago.

With his stellar results in 2006, Arnold Chan Kwan-yeung skipped Form Seven and went straight into a business studies course at Chinese University that led to a job in asset management at Goldman Sachs. Joining the investment bank proved to be something of a culture shock.

"Goldman Sachs is an international bank. I was a student with little exposure to overseas culture. Although I joined university exchange programmes in Denmark and the US, I only hung out with Hongkongers. I was introverted when I was younger and didn't know how to get along with foreigners. So there was a big learning curve and a lot of stress when I first joined the bank," Chan says.

"People at the bank knew I was a straight-A student and wondered whether I was a typical swot who only knew how to excel in exams."

But the training and exposure he received at Goldman Sachs turned him into a much more confident and sociable person, Chan says.

"My experience in dealing with clients also boosted my presentation skills."

By the time he left to pursue an MBA at Harvard in 2013, Chan's annual salary came to more than HK$1 million a year.

But he has struck out in a different direction following a brief summer stint in Beijing to work for Teach for China, a charity that enlists top graduates as teachers in underprivileged schools. Modelled on an American NGO, it proved so inspiring Chan took last year off from his studies to set up a similar organisation in Hong Kong, Teach4HK.

"My 10 As were useful then as I could get more media to interview me for Teach4HK. But beyond that, it did not give me any other advantage over others. I don't even put it on my CV as people don't really care about such things once you start working."

All the same, Chan believes education helps boost social mobility for the working class.

"Many students from grass roots families are failures in the exam system. There are about 50 schools which have never had one student advance to university. The students don't have the resources available to more affluent children to nurture their talents," he says.

However, Teach4HK has recruited six graduates to work in schools serving poor communities, paying them HK$10,000 each month as a subsidy. "They are passionate graduates with leadership qualities who have a mission to help the underprivileged students."

Now back at Harvard, Chan says he shuttles back to Hong Kong to work on the charity.

"I will join Teach4HK full time after completing the MBA. I won't get any pay but I want to make a contribution in education."

In 1995 he became the first ever student in the New Territories to achieve 10As in public exams; however, Chow Shing-yuk has taken a road less well travelled.

He started work conventionally enough at an international consultancy after earning an economics degree from Stanford, but after three years he left to become a professional gambler in Macau.

"I only played Texas hold'em [a form of poker] which requires skill, unlike games of pure luck like baccarat. You can make calculations to win - it is like playing chess or bridge. For eight years, I hardly saw daylight and stayed in casinos all the time. In the first four years, I only made several thousand dollars a month, and had to live off my savings from working at the consultancy. But I persisted, believing that I would win eventually," says the 37-year-old.

"I love unconventional challenges. I was not a top student in junior forms, but as there had never been any straight-A students coming from the New Territories, I set myself a challenge to become the first one."

Chow, who lived in temporary housing as a child, saw gambling as another unusual challenge and accumulated HK$30 million in winnings by the time he left the poker tables in 2010.

He used his winnings and proceeds from property investment to launch logistics start-up EasyVan in 2013.

"I quit gambling as it doesn't create anything. Launching EasyVan was another challenge and gamble for me. I want to build a home-grown IT company. It's something I am passionate about," Chow says.

A sort of Uber service for goods delivery, EasyVan has now signed up more than 30,000 drivers in cities from Bangkok to Singapore and Taipei and records about 10,000 transactions every day. The company, named LalaMove outside Hong Kong, secured US$20 million in funding this year to finance expansion in the region.

It has yet to turn a profit, but Chow hopes to start charging users in about two years' time, when he expects the user base to have grown to a critical mass.

When it comes to criteria for success, Chow says a person's background, intelligence and academic aptitude can't compare to hard work.

"IQ and analytic ability are overrated. Public exams are designed by academics to train people to be like academics. So there's a mismatch between the things you learn at school and the skills required in society," he says. "Exam results are not that important. The key is to persist in doing something you have great passion for."

Now a cardiothoracic surgeon at Queen Elizabeth Hospital, Li Ki-kwong exemplifies how education can offer a way out of the poverty trap.

Li lost his father to cancer when he was 10; and his family lived on public assistance when he was growing up in a Tseung Kwan O public housing estate. But he applied himself at school and his 2002 exam results got him into the University of Hong Kong's medical school.

Recalling his student days, Li says he has never felt inferior about his background.

"Many students in medical school come from middle-class families. Affluent kids can join many extra-curricular activities and overseas exchange programmes to broaden their horizons. I never joined any [such] programmes. But hard work is what matters most at the end of the day."

Echoing the EasyVan founder, Li says: "If you study hard and have good results, you can study any university subject you want and do a job you are passionate about. But how your future pans out after you come out to work depends on your job performance and attitude."

His perfect score in the 1994 public exams totally changed his life, Lee Tin-man says. For one, it earned him a full scholarship to study electrical engineering at the University of California, Los Angeles.

The media attention was overwhelming, too.

Like many bright young men in Silicon Valley, Lee was quickly involved in a start-up - within a year of earning his undergraduate degree he had co-founded a company designing computer systems for broadband networks.

But poor presentation and communication skills let him down when he sought to raise funding, he says. "Good academic results don't mean much - there are so many top-notch people in the world."

All the same, he found himself at a disadvantage in his day job at an electrical components company: "Whatever ideas I put forward, no one paid any attention. They only listened to people with doctorates. That's when I knew I had to further my studies."

Lee duly earned a master's in electrical and laser engineering but in the process discovered he was fascinated by an unrelated field - image processing.

"I felt lost as laser engineering has no relevance to image processing at all," he recalls.

But a news clip about Hong Kong-born researcher Tony Chan Fan-cheong (now president of the University of Science and Technology) prompted Lee to reach out to congratulate the image scientist who had overseen scholarship students like himself at UCLA. And the contact proved timely. "He eventually took me under his wing for my PhD in biomedical image processing."

Lee now works for biopharmaceutical company Amgen, managing their imaging processing centre.

Six years ago, he discovered another interest while going on hiking trips in the US - wildlife photography - and has since earned a number of awards for his images.

Lee says he is lucky to have found his true passion when he was still young.

"Hong Kong's education system advocates absolute dedication to excelling in public exams. But no one guides you to find your future path. I didn't know what I loved most until I discovered image processing. I only had this awakening because of my curiosity to attend talks beyond my master's subject. So people studying in university should not pass over any opportunity that comes their way to know more people and subjects."