There is nothing diva-ish to his reticence, quite the contrary. The chat show host is talking about his father’s death and the dreadful impact of Parkinson’s disease.
He is also conscious that it is not his story alone to tell.
“It’s odd,” he admits. “I am not the keeper of this story, it is my sister’s and mum’s too but because of what I do, I am the one who is asked about it.”
He has agreed to an interview in the hope of fostering a better understanding of Parkinson’s and raising money for research.
“The big push is for more specialist Parkinson’s nurses,” he says. “There are 334 at the moment and we need 400 just to cover needs now. Over the next 10 years we are going to need a hell of a lot more.”
We are sitting in the boardroom of a stylish London club where he will soon be meeting and greeting patients and supporters of the charity Parkinson’s UK.
“For some of the people coming today it is a major effort just to be here. I am just in awe of them,” he says. “When you meet people with Parkinson’s who are doing things such as cycle rides for charity and absolutely not giving up, it takes your breath away, particularly when you think how phenomenally lazy most of us are.”
Parkinson’s is a degenerative condition which causes progressive loss of motor control as the brain cells producing the chemical messenger dopamine are destroyed.
At first there may be only vague clues that something is wrong, such as stiffness in a hand or leg, your handwriting getting smaller, losing the sense of smell, problems sleeping, anxiety and depression.
More serious symptoms including tremors, shaking, loss of balance, rigidity and slowness of movement do not appear until around 80 per cent of these dopamine-producing brain cells have been lost.
Research continues to shed light on the condition and there is hope that in the future gene therapy or stem cell treatment may provide a solution. As yet there is no cure, although there are drugs which reduce symptoms.
Around 127,000 people, one in 500, in the UK have Parkinson’s and although most are diagnosed after the age of 60 it can strike much earlier. One in 20 people with the condition is under 40.
Graham says: “As awful as it was for my father to get a diagnosis in his 70s, can you imagine being in your 30s? You can’t imagine it,” he adds, in answer to his own question.
His father William Walker (Norton is a stage name) was diagnosed 10 years ago and died just three years later. Graham says: “Once he was diagnosed it all happened very fast. It’s different for everyone but it hit him like a ton of bricks.
“I have no idea how I would react if I was given the news that I had something like Parkinson’s but I like to think I would fight it and continue to find a quality of life.
“My father decided quite early on that it was a fight he couldn’t win so he declined at an alarming speed. It was a very difficult time and I think his mental attitude really frustrated my mother.
“But Parkinson’s is such a big thing to pick a fight with.”
William had always been physically strong, “In that Irish way,” says Graham.
But suddenly the powerfully built man who used to let his son win at football was reduced to a frail hologram of his former self. “Like a baby bird that had fallen from the nest,” says Graham.
“Parkinson’s is especially cruel. It doesn’t even do you the favour of killing you. It just moves in and with an awful efficiency simply packs up your quality of life.”
Simple tasks require Herculean effort and as sufferers become increasingly dependent the pressure on families can become unbearable.
“Mum was looking after him but we knew that was going to make her ill. Luckily we got him a room in the local nursing home.”
Between episodes of his chat show he would fly back to Ireland and each time was shocked at how much his father had deteriorated.
“I had heard of Parkinson’s and knew some of the symptoms but that was it. I didn’t particularly know about treatment or his prognosis and I certainly didn’t realise how serious it was.
“It is a real turning point, just being in hospital and having the doctors treat you like an adult. You want to say, ‘Don’t be telling me about this stuff, I am just a kid.’ Suddenly you see your father in a very different way.”
When the end came it was a relief. “In a way that’s the nice thing about death, suddenly all the things that were horrible to endure, all the pain, all the indignity are gone,” he says. “You could not fault the care he received but Parkinson’s is such a very cruel condition.”
Yet there were moments of joy as neighbours came to pay their respects at the family bungalow in Bandon, County Cork. “Nearly every visit ended up with us all laughing at something my father had done or one of his stories being retold,” says Graham.
“My father left many legacies but the one that means most to me is how much closer I’ve become to my mother and sister.”