By Maria McCann
BBC News NI
Jimmy Cooper turns 80 in November but has no plans to give up his nursing career anytime soon.
He works in the intensive care unit at the Royal Victoria Hospital in Belfast.
Although he briefly retired at the age of 69, he came back "after about four months" because he was bored.
"I really enjoy the job I do. It is very satisfying," Jimmy tells us as he works on the ward.
'What's up doc?'
A chance meeting with a matron and her deputy in a cottage hospital near Brighton in the 1970s shaped the rest of Jimmy's life.
"I was wandering around the corridors inside and all I hear is: 'What's up doc?'" he explains.
"I saw these two little ladies sitting in a cupboard... having a cup of tea.
"I quickly thought: 'I have got to make an excuse why I'm in here', so I said I'd come to pick up some leaflets about jobs."
After a chat, Jimmy left his name, address and telephone number and was signed up to a training course some months later.
"When I trained I wasn't even allowed to listen to the lecture about females. I would be asked to sit on the stairs," he says.
"Even after I qualified I couldn't work on a female ward. In fact I couldn't even go through the door of a female ward.
"So I was actually a qualified nurse for two years before I saw a female patient."
'A bomb's gone off'
Among his patients over the years were Conservative Party politicians injured in the Brighton bombing in 1984.
"I was the manager there of the unit. I got a call to say: 'Come in, there's a bomb gone off,'" says Jimmy.
"I thought the staff were joking and put the phone down. The phone rang again so I was there… I looked after the politicians."
For almost 20 years, Jimmy has been tending to seriously ill patients on the intensive care unit (ICU) ward in Belfast's Royal Victoria Hospital.
Heather O'Connor, who works as a sister on the ward, was mentored by Jimmy when she was a newly qualified nurse 16 years ago.
"He is a fantastic teacher and he had lots of patience with me as a junior nurse," she says.
"It's good fun - we all like to get our tea breaks with Jimmy in the evenings.
"We call him Granda and he has a fair few granddaughters in our ICU and we're all very fond of him."
Dr Brian McCloskey, a consultant on the ward, has worked with Jimmy for almost 20 years.
"Jimmy is one of the most caring and compassionate, enormously knowledgeable, experienced and unflappable nurses I could ever work with," he says.
"He came on to the ward last weekend when we were both working and he took over a patient, really quite a difficult patient, and I just thought to myself: 'That patient is in safe hands.'"
With five decades of experience in the health service, Jimmy would be forgiven for putting his feet up.
But he hopes to extend his contract for at least another three years.
He says "keeping up" with younger members of staff keeps him "fit and young".