To reach the age of 100 is an impressive feat.
Becoming Britain's oldest man quite another.
Imagine then discovering that a fellow centenarian at the other end of the country is not only the same age but also shares the same birthday!
For Bob Weighton, born in March 1908 when Edward VII was King, that is exactly what happened.
Two years ago he saw a story about Alfred Smith, from Perth in Scotland, and sent him a letter.
Today, the pair both celebrated their 109th birthday.
Mr Weighton said: "I saw a story about him and saw we were both the same age and shared the title of oldest man, so I sent a letter to him. We send each other cards now on our birthday."
The secret to such longevity? "I haven't the slightest idea," said Mr Weighton, originally from Hull.
"I don't have any rules because I've eaten all kinds of food, I'm not on a diet of any sort and I've managed to escape dying from various operations."
After leaving school at the age of 17, Mr Weighton trained as Marine engineer until 1925.
He then met and married his wife Agnes in 1937 while training to become an English teacher.
Over his lifetime, he has lived in Japan, Taiwan, Canada and the USA.
Mr Weighton and his wife, who passed away in 1997, spent much of their retirement volunteering as marriage councillors and helping at youth groups in their town.
In his spare time, he still makes woodwork for charity
"It takes me a lot longer to do anything, like getting up to get the tools and sitting down again. It all takes a lot more time," he said.
"If I promise somebody to give them a windmill or a lighthouse or a puzzle or something, it takes much longer than I tell them."
What is the biggest change he has seen over his long life? "I think the attitude to women has changed an enormous amount... and the speed that which people can move around and the frequency is enormously different," said Mr Weighton, speaking from his home in Alton, Hampshire.
"Nobody ever thought about flying anywhere.There were a few rich people who could hire a plane and fly to Paris, which was enormous adventure, and things that we ordinary people could only read about in the newspapers."
In an interview with ITV Meridian ahead of his 109th birthday, Mr Weighton, who has 10 grand children and 25 great grandchildren, explained that he now declines his annual card from the Queen.
"I'd already received one every year and since it's the age of austerity I thought I would save the country a little bit on postage and printing," he said.
"I don't want a whole row of them, there's no point in that."
Mr Weighton, who lived through both world wars, has witnessed many a momentous occasion - and on the day that Article 50 was triggered, he had a message for the prime minister.
"I'm a bit regretful that Theresa May has decided to initiate the Brexit discussions on my birthday and she never asked my permission," he said.
Mr Smith said he was glad to receive a birthday card from Mr Weighton, but admitted he was feeling his age.
Speaking to STV, he said: "I can't just do everything that I'd like to do. I'm very careful when I walk, if we go out.
"I never thought I'd reach this age (but) I feel very good for 109.
"I don't have any pains and I sleep well."