Hannah Thornton is used to being around seniors suffering from loneliness - so when she overheard two strangers befriend each other on the train, she could not contain her happiness.

Thornton volunteers for a charity in Sheffield called Age Better; a nonprofit dedicated to encouraging friendships amongst the elderly in order to reduce social isolation during their golden years.

While she was riding a train to Liverpool at the start of February, she heard two older men strike up a conversation a few seats away.

"This time last week, I got the train to my Grandma's and shared part of my journey with 2 lovely men," wrote Thornton. "They'd never met before but instantly hit it off and laughed like they'd been best friends for years."

Touched by the sweet exchange, Thornton scribbled a quick note to the duo, commending them for their neighborly attitudes.

"I didn't want to interrupt your conversation but I wanted to let you know how heartening it's been listening to you chatting on the train this morning," wrote Thornton.

She went on to explain how she volunteered with Age Better and how they strived to make people feel less alone.

"We encourage people all the time to be neighborly and to share a smile or a nice word with another person, so it's been lovely to hear you both doing an abundance of that!"

She finished the note by saying that they "both seemed very young at heart" and Age Better was always looking for volunteers if they were interested in sharing their charms with others.

Later that week, she got an emailed response from one of men who was named Bill.

"Thank you for the note you gave me as you left the train yesterday," he wrote. "You made 2 old men very happy - although I don't consider myself as old. 63 is the new 40!!!!"

He went on to say that he and the other man, an 80-year-old gentleman named Morris, had been delighted to chat with each other on the train ride. In addition to explaining where he and Morris had been headed, Bill commended Thornton for her charity work and said that he would be interested in working for the organization in the future. Also, he was more than delighted to be a neighborly example for his community.

"[Morris] was a really engaging and lovely person to talk to," said Bill. "I didn't manage to open my paper or look at my iPad once. I wish every trip was like that."

Thornton took photos of both of the letters - from her and Bill - and posted them to Twitter where they have since gone viral.

They have already been shared over 40,000 times, and the young volunteer says that she is glad that they can now inspire others to be more friendly.

This time last week I got the train to my Grandma's and shared part of my journey with 2 lovely men. They'd never met before but instantly hit it off and laughed like they'd been best friends for years.

I scribbled a note to them as I got off the train...and I got a reply!!?? pic.twitter.com/eWA7hiNEim

— Hannah Thornton (@hannah_shef) February 9, 2018

This time last week I got the train to my Grandma's and shared part of my journey with 2 lovely men. They'd never met before but instantly hit it off and laughed like they'd been best friends for years. I scribbled a note to them as I got off the train...and I got a reply!!?? pic.twitter.com/eWA7hiNEim

Pass On The Positivity: Click To Share (Photo by Hannah Thornton)