Prince Philip sometimes struggled to mask his true feelings on royal visits.
But he did not have to put a brave face on it during one of his last public appearances in Northern Ireland almost five years ago.
For there was no disguising the Duke of Edinburgh's obvious interest in hearing about the bravery of an inspirational war hero who he and the Queen had come to honour in Co Antrim.
I had seen his Royal Highness glaze over before at the monarch's side as she fulfilled her sometimes more mundane engagements.
But this was different. In June 2016 the Prince's body language and facial expressions showed that he was fascinated with the story of Sergeant Robert Quigg as a bronze sculpture of him was unveiled in front of old soldiers and an Irish Guards band in his home town of Bushmills.
The Prince was in good form from the start. As soon as he stepped out of his royal car he laughed and joked with his welcoming party and paid extraordinary attention to a chain of office worn by the local mayor, Maura Hickey.
During the opening addresses from a covered dais, the Duke could be seen enthusiastically perusing a booklet which told the tales of heroism by Victoria Cross winner Quigg, who courageously saved seven of his colleagues on the first day of the Battle of the Somme in July 1916.
The Prince, a one-time Royal Navy commander, listened attentively as Leonard Quigg told how his great-uncle searched in vain for his platoon commander Lt Harry McNaughton in No Man's Land under heavy gunfire. But on each of his seven sorties into danger he brought back a wounded soldier.
Mr Quigg revealed the Queen and Prince had actually met his brave ancestor in Coleraine in 1953 during the monarch's Coronation tour.
After the Queen unveiled Sgt Quigg's statue in the Main Street of Bushmills, Prince Philip took the covers off a nearby commemorative stone, which was made up of seven bronze hexagons like the stones at the nearby Giant's Causeway, where the royal visitors had a short time earlier heard tales of another hero - a mythical one - Finn McCool.
Only a small number of visitors were at the world famous tourist attraction, though thousands of people packed Bushmills to see the royal couple.
However, many of them didn't even get a glimpse of the visitors.
Some local residents had been waiting behind crush barriers for six-and-a-quarter hours, but the Queen and her husband only stayed in the town for 20 minutes.
Security had been tight for the visit, with dozens of police on duty. Invited guests and the media were all searched in a marquee at the Bushmills Distillery before being taken by bus into the area around the Quigg statue.
Before leaving Prince Philip chatted with relatives of another Victoria Cross winner, William McFadzean, who were in Bushmills for the Quigg commemorations.
The Duke was told how Private McFadzean died after a box of grenades fell into a trench before the start of the Battle of the Somme and the Belfast man threw himself on top of them before they exploded.
After their flying visit to Bushmills, they then travelled on to Royal Portrush Golf Club for a civic lunch hosted by Causeway Coast and Glens Borough Council.
In stark contrast to Bushmills, the only sign of security at the club was the presence of two uniformed PSNI officers at the door.
One of the invited guests, football and motorcycling pundit Liam Beckett, recalled how Prince Philip listened patiently as an official made the introductions, adding: "He told the Prince all the football clubs I had played for and who I had been involved with in the motorcycling world.
"The introduction must have gone on for five minutes. I was as bored with hearing about me as the Prince must have been.
"Afterwards the Prince, who had never let go of my hand, said to me: 'And you're still alive?' To which I replied: 'And kicking'. He laughed, and I must say that my opinion of him changed that day. I found him to be a very nice man."
It wasn't clear if Prince Philip's quip to Mr Beckett had been borrowed from his wife's joke the night before, when she replied to a question from Deputy First Minister Martin McGuinness about her health with a joke: "Well, I'm still alive anyway."
Despite a hectic schedule the next day the Prince, who had just turned 95, never looked like flagging and he and the Queen travelled back in time on board a Railway Preservation Society of Ireland steam train from Coleraine to the tiny village of Bellarena for the opening of two new platforms.
The royal visitors had travelled along the same route during the Coronation tour in 1953.
On her return to Ballarena the Queen unveiled a plaque, little knowing that it would soon be the centre of controversy.
Just 24 hours after it went up it was taken down, and Sinn Fein's Infrastructure Minister Chris Hazzard said Northern Ireland Railways had advised him the move was because Ballarena was unmanned and officials were concerned that the plaque could have been vandalised.
That 2016 visit was Prince Philip's last major trip to Northern Ireland in the full glare of the media.
But it was highly appropriate that his very final engagement, in May 2017, was to meet 115 gold award recipients in his cherished Duke of Edinburgh's scheme.
The Prince had only just announced that he would be retiring from public duties the following autumn, but guests at the ceremony said that he was in a relaxed and jovial mood as he chatted informally with a large number of people who told them just how much his scheme had meant to them.
One said: "When the cameras were off him he was full of life, full of jokes and full of fun. It's hard to think that was his last visit to Northern Ireland. He'll be greatly missed and fondly remembered."