Nick Butter said he felt “reborn” after setting the world record of running the 26.2 mile race in all 196 United Nations-recognised countries following completion of the Athens Classic Marathon in Greece on 10 November.
The former banker took 22 months to complete the challenge, which he undertook in aid of Prostate Cancer UK, and was inspired to do by fellow runner Kevin Webster who he met during a race in the Sahara Desert.
Webber was diagnosed with prostate cancer in 2014 and, according to Butter, was told he had just two years to live.
“Six or seven months into the journey I started to appreciate exactly what he [Webber] had,” Butter told the Press Association.
“I don't think you can truly understand it [life] unless you are faced with something like Kev has had, you don't really understand the value of life until you're told you're going to die,” he said.
The 28-year-old said that he suffered food poisoning nine times and was bitten by leeches in Nepal during his epic mission.
Butter described races in Kuwait and Bangladesh as the toughest due to the high temperatures, while Guatemala came top as his favourite marathon.
But it was the people Butter met along the way that he said made his experience so memorable.
“I counted up all of my new contacts in my phone book - it's 2,411 new people that I have linked up with,” he said.
”On Christmas Day I woke up to messages from 32 different nationalities wishing me happy Christmas.“
Butter’s next plans include doing talks about his experiences, including speaking events in schools.
”I have come away basically feeling reborn into a world where I thought I was lucky before, and I thought I was one of these people who really valued it [life],” he told the Press Association.
“But now I understand that I didn't understand at all - not completely - how really lucky we are,” he said.
Butter’s message was for people to recognise the fragility of life and value the people in it.
“My message is, I don't want people to just assume that they'll be able to get to retirement, or live that dream tomorrow,” he said.
”If you've got time go and do it. It doesn't have to be a big thing - just hug each other for a little bit longer, read another story at bed time, cycle to work instead of sitting in traffic.“
So far, Butter has raised nearly £70,000 of his £250,000 target for Prostate Cancer UK.