Walter Harris had never had cause to feel real loneliness until his wife of 46 years died in 1998.
Mr Harris, who was brought up in Llanhilleth near Newbridge where his family was a constant presence, said he suddenly felt very alone.
"I was absolutely heartbroken, I was shattered basically. It was the end of the world," he said.
"Being lonely is not to do with getting help, it means you exist in a vacuum. You hardly exist, you feel like you don't have an identity."
Mr Harris, speaking as the results of research for the BBC are unveiled about how the UK has changed in the past 40 years, had seen his son move away to university and his daughter move to south-east England.
He no longer had his extended family on his doorstep.
"It used to be in Llanhilleth that my grandmother and grandfather lived down the road and we lived with my aunties," he said.
"There were relatives all around you really. That's how it used to be in those days but it's not like that now."
After his wife died, Mr Harris moved from their home in Swffryd to Pontnewydd near Cwmbran to be closer to Newport, where he was studying at university.
"I found it difficult to pick up the pieces because it was always the two of us," he said.
"I didn't realise until after she had gone how supportive she had been. You have nobody to discuss your personal problems with."
Mr Harris, a driving instructor for 25 years, volunteered for Age Concern Cymru and was put in touch with Age Concern Torfaen, which had a big impact on his life.
His love of technology led to him eventually becoming a mentor to people attending Age Concern Torfaen's IT classes in Pontypool.
He is now a well-known figure in his community and is secretary of a variety of groups including Cwmbran 50+ Forum.
Mr Harris has seen some of the benefits of modern life, such as how technology enables families to stay in touch across large distances.
"I've got a mobile phone so I text a lot. All of my family use texts," he said.
"There's emailing and [online] messenger. I used to talk to my grandson when he was in New Zealand through messenger.
"I keep in touch with my cousin who lives in New Zealand and we email two or three times a week sometimes."
He is helping other older people overcome their fear of technology which can often allow them to stay in closer touch with their own families.
"Older people are afraid of technology but if you use technology to ring your son, that's not technology, it's a phone," he said.