Travelling along Symonds St on his way to work, a 15-year-old Owen Glenn would gaze wistfully at students making their way into the University of Auckland.

The promising student's dreams of becoming a lawyer were dashed when his father's career was cruelly cut short by illness.

Fast forward five decades and Sir Owen, as one of New Zealand's most successful entrepreneurs, would give $7.5 million to the university for development of its business school — allowing generations of young Kiwis the chance to reach their goals.

His donation in 2002, believed to be the largest such private contribution in this country's educational history, is part of the more than $50m.

Sir Owen says he has given to causes and to foster and comfort those in need.

And the 77-year-old businessman who turned $2000 into an estimated $400m-plus fortune, has revealed he intends "to leave a substantial amount if not [the] majority" of that wealth to continue to support others.

"I think a lot of young New Zealanders, who otherwise would not have had the opportunity, will do very well [out of it]."

Sir Owen is resting at his villa in the Fijian island of Malolo Lailai. He has another year's globe-trotting schedule ahead of him while he continues to fight cancer. That has given him even more time to reflect on the legacy he will leave with his fortune.

Slimmer after shedding 18kg, he is sticking to his New Year's resolution and is back on the strict diet he went on following surgery because a return of liver cancer.

The disease was first detected in 2012. During a routine medical test, "they were probing around with an ultrasound — and they suddenly saw this thing in the liver".

A mass "the size of a golfball" was detected. "So they took half my liver out. I was all right for a while, then it came back and they did some minor operations."

A more major surgery was performed last year, after which he went on the diet — "no sugar, no alcohol, no carbohydrates".

"I had to give up rice and pasta and bread, and drink soda water. I had a little break over Christmas for about 10 days, and now I'm back on it."

At 70kg, he expected to return to the 67kg he had dropped to with the regimen over the past eight months. "I'm 5ft 7 inches, so I don't want to get any skinnier, because I'll be like a chicken."

"I collapsed, fell over, went into a coma, and then they had to drill holes ... to release the blood pressure from my skull — it came out like a fountain."

He has also had cataract operations on both eyes over the past six months. "And I'm seeing colours five times brighter than they ever were."

He will not let health issues affect his plans. Already in his calendar this year are trips to Bali, Ireland, London, France, Malta, Egypt, Inner Mongolia, China, India and South Africa.

He will be in Australia for the Melbourne Cup week. "Flemington, I should have at least eight to 12 horses running."

He is also awaiting the release of a judgment in a dispute between him and former business partner and sports club owner Eric Watson, which was heard last year in a High Court trial in London.

Sir Owen is not willing to discuss details, but says the judgment is expected in March or April. It has previously been reported that the court battle appeared to be the latest chapter in a war over assets worth more than $200m.

Asked what he wants done with his fortune, he says: "I've already planned all that. Apart from my family, I am intending to leave a substantial amount if not the majority to philanthropy — to sport, to education and to health, and to [his new charitable organisation] the Helps programme. But all my family will be looked after.

"I will basically give it in various invested trusts, in which I've put a lot of time and effort into; investing in property and horses and all sorts of things.

"And it should be in perpetuity. I think a lot of young New Zealanders, who otherwise would not have had the opportunity, will do very well [out of it]."

Sir Owen has a colourful and at times controversial past. He became a household name when he donated about $100,000 to New Zealand First's 2008 election campaign — a donation leader Winston Peters was censured by Parliament after failing to declare.

He struck up a part ownership of th Warriors with Eric Watson, but sold his shares back to Watson in 2015 after the pair's working relationship soured.

He also funded an inquiry into domestic violence in New Zealand to the tune of $2 million but it was hampered by numerous resignations after it was revealed that in Hawaii in 2002 the billionaire pleaded no contest to a charge of physically abusing a woman. He said in 2013 there was no truth behind the allegation.

Sir Owen — made a Knight Companion of the New Zealand Order of Merit in 2013 for services to philanthropy — says his upbringing inspired him to give to others. "My parents didn't have much themselves but always shared what they had."

Born in Calcutta (now Kolkata), he was 12 when his family moved to New Zealand, initially settling in Mt Eden, Auckland. Academically advanced, he went from Form 1, where he was top of the class, straight to Form 3 at Mount Roskill Grammar. Sporty, he played hockey — representing New Zealand schoolboys — soccer, cricket and rugby.

"Very quick" but "very light" he was on the wing in rugby, where he "used to get belted around a bit — broke my nose".

Aspirations to become a lawyer were put aside when his father, an accountant, got cancer and had a lung removed.

"Our whole family fortunes came to a stop. He couldn't afford to send me to university so I had to go and get a job."

Joining the Bank of New Zealand, he eventually became a teller in an inner-city branch "and within six months, at the age of 18, I was head teller".

Deciding at 20 he wanted to journey to Europe, he worked at a wool store, timber yard and foundry to save for his trip. Over his 18-month stay there, he was variously a butcher, plumber, drove an elevator at Harrods in London, and worked in a fruit-canning factory.

When he returned his parents asked him what he enjoyed and what he wanted to do for a career. "I said travelling, so I went down to TEAL (now Air New Zealand) and I saw the personnel manager." He started in the cargo department, where he became "the go-to guy".

"A lot of people said 'could you send this, in this quantity, on this passenger plane?' And I knew the answers."

Headhunted by an American-based air cargo firm — "they offered me a car. I'd just got married, I needed a vehicle" — he moved to Sydney with the company. Offered a position with another company in London, he was involved in an amalgamation of two businesses creating a major freight firm.

Returning to Sydney, in 1976 he and a partner set up their own freight company, Pacific Forwarding Group.

Sir Owen says he started with $2000 "and a very accommodating bank manager".

"We had to mortgage our homes and worked our butts off."

He founded Direct Container Line (DCL) in 1978, running the company from California after he and his partner separated their business interests.

Sir Owen started out sharing one of eight desks in a container for an office and built DCL into the second-largest exporter of goods in the US.

In 1991 he was presented with a US "Entrepreneur of the Year" award, which he describes as "a bit like the Oscars". In 2008, he was appointed an officer of the New Zealand Order of Merit, for services to business and the community.

"That was a real thrill because that was acknowledging my entrepreneurship."

DCL became OTS Logistics Group following a merger with Brennan International and Conterm Consolidations Services. Sir Owen sold OTS Logistics in 2012 — reportedly for a little under $500m.

"I had a reasonably natural instinct for marketing and salesmanship. And I worked very hard and constantly."

He opened about 180 offices and interviewed 6000-7000 people for jobs along the way. His work regimen cut into family time. "I could have spent more time with my kids to be honest. But I had to feed them and clothe them and educate them."

Sir Owen has three children from his first marriage, which lasted 14 years, and three from his second, which lasted 16 — five daughters and a son.

He says he gets on well with his children, four of whom were at Malolo Lailai during the New Year holidays along with some of his 11 grandchildren.

He does not have a partner. "I do have a lot of lady friends, but just acquaintances or friends or people who have worked for me and stay in my life. I'm single, 77 going on 78."

Sir Owen gave more to the University of Auckland's business school with gifts of $5m in 2015 and $2.6m in 2017 to support innovation and entrepreneurship.

Last year he pledged $5m towards the creation of a proposed medical school in Waikato, aimed at reversing a shortfall of primary-care doctors, especially in provincial and rural areas.

His support of charitable causes began "at least 40 years ago", and although he doesn't know exactly how much he has given — "it would be in excess of $50m".

He has supported organisations, groups and individuals here and around the world — including Samoa, India, China, Myanmar and Sri Lanka.

He sent kitsets to build new homes in Samoa after it was ravaged by the 2009 earthquake and tsunami, and donated $1m to help the people of Christchurch after the 2011 quake.

He is "going to put a lot of money behind grommet surgery to give kids hearing for the first time" in India, and is opening 15 clinics in Myanmar for eye surgery, including cataractwork.

The Helps (Health Education Love Protection and Spirituality) foundation he has recently established will operate "like the Peace Corps".

"I'm attracting young achievers between 18 and 25, training them and then sending them to various locations internationally to help with local schools and prepare people for adult life.

"We're starting with 15, and 25 next year and 50 the year after. We will continue that in perpetuity I hope."

Sir Owen was moved by the "courage and great spirit" of a younger Kiwi samaritan, Eva McGauley.

The 18-year-old was diagnosed with a rare type of head and neck cancer at 15. Following intensive chemotherapy and radiotherapy, she found out her cancer had spread and was terminal. In between bouts of treatment she raised more than $70,000 for others.

Learning of an appeal to raise $60,000 for the teen's treatment with a drug she believed was keeping her alive, Sir Owen offered to make up any shortfall.

The amount was met by the public, but he has offered her and two carers a week's stay at his villa in Malolo Lailai.

There were concerns around medical facilities, he says, so he offered McGauley and her family a stay on his 34m superyacht Ubiquitous, instead, being moored at the Gold Coast for the Commonwealth Games.

Sir Owen had earlier helped another teen who had terminal cancer. He sent the Melbourne 17-year-old on a holiday to Kenya with her father.

He had encountered her at Hamilton Island, where she told him of her illness. "I said, 'What is it you'd really like to see in your lifetime?' She said, 'Well I've always loved wild animals. I've never ever been on a safari — and I guess it's too late now'. She didn't know who I was. I said, 'Oh well, you never know'. And the next day I arranged it all."