Becoming a billionaire would be, for most of us, the very apex of achievement - and a very unrealistic dream come true.
Chuck Feeney lived that dream but he wasn't content simply with becoming a billionaire - no, he set himself a further a goal.
To give away his entire multi-billion dollar fortune while he was still living.
The 89-year-old American businessman has now achieved that, donating almost $9bn (£7bn) worldwide.
And through his private foundation the Atlantic Philanthropies, Mr Feeney, born to Irish-American parents, gave $570m (£447m) to causes in Northern Ireland over four decades.
Who is Chuck Feeney?
Charles F Feeney was born in Elizabeth, New Jersey in 1931, during the Great Depression.
His mother worked as a hospital nurse and his father was an insurance underwriter.
The philanthropist traces his family history back to County Fermanagh, where his grandmother was brought up close to the village of Kinawley.
The entrepreneur made his money selling luxury duty free goods to travellers across the world, but he rejected the trappings of wealth himself.
Conor O'Clery, who wrote a biography of Mr Feeney, said: "He read and was very impressed by Carnegie's famous essay 'Wealth', which says such things as 'to die rich is to die disgraced'."
He went on to found the Atlantic Philanthropies in 1982, an international organisation set up to distribute his fortune to good causes and projects that he supports around the world.
The foundation's main areas of interest are health, education, reconciliation and human rights.
For the first 15 years of his philanthropic mission, Mr Feeney donated money in secret leading to him being dubbed the James Bond of philanthropy, only emerging from anonymity in 1997.
According to Mr O'Clery, his five children (four daughters and one son) have been left money through their mother, Mr Feeney's first wife.
He now lives in a two-bedroom apartment in San Francisco with his wife Helga, having travelled extensively to examine projects to donate to.
NI's 'big bets'
Queens University Belfast (QUB) was one of the biggest beneficiaries of Mr Feeney's grants from 1993-2015, being gifted a total of $132m (£83m).
It also received the single biggest donation from the Atlantic Philanthropies, when it was gifted $24m (£15m) in 2012.
It was for the university's Institute of Health Sciences Centre for Experimental Medicine.
Nathalie Trott, from Queen's, said the grants had "changed the lives" of students and had provided the university with "state of the art facilities."
"The doors of the Atlantic Philanthropies may have closed in Belfast, but Chuck Feeney's legacy will live on for generations."
Another cornerstone of Mr Feeney's philanthropy in Northern Ireland has been the promotion of integrated education in the pursuit of reconciliation and peace building.
Down through the decades, it is understood about £8m has been gifted to the Integrated Education Fund for various projects and the area is listed as the first sector funded in NI by the Atlantic Philanthropies back in 1991.
One of the schools that benefitted from hundreds of thousands of pounds is Rowandale Integrated Primary School in Moira.
Principal Frances Hughes said Rowandale would not be in existence today without Atlantic Philanthropies' support.
"In 2007, when the school opened, enrolment began with 18 children and this year we have an enrolment of over 300," she said.
"The pupils here would have had absolutely no idea (about Chuck Feeney's role) - I would love to tell them that story though and I think they would really enjoy it."
Since 1996, when the Integrated Education Fund received their first grant from the Atlantic Philanthropies, there were a total of 33 integrated schools, which had risen to 62 by the time their funding drew to a close in 2014.
The funding has helped to establish 21 integrated primary and eight secondary-level schools and in those 18 years, pupil numbers overall have risen from 7,000 to 22,000.
Christopher Oechsli, president of the Atlantic Philanthropies, said it was "an honour" to support so many projects in Northern Ireland since first beginning its operations here in 1991.
"It's heartening to see the progress made and the way groups Atlantic supported continue to drive change in these challenging times," he said.
"That's the legacy."
According to biographer Conor O'Clery, Chuck Feeney is "very happy" that he has now completed his almost 40-year mission and celebrated the milestone with wife Helga.