The 23-year-old England international experienced the pain of the 2020 wooden spoon year at the Broncos but decided to re-sign with the club rather than look elsewhere.
Ahead of Saturday night's preliminary final against the Warriors at Suncorp Stadium, Farnworth explained his thought process.
"Deep down there was an unspoken pact to stick together and hopefully win a comp," he said.
"Myself, Payne (Haas), Fleggy (Thomas Flegler), Kotoni (Staggs), Kobe (Hetherington) … there are so many names who came through the 20s together.
"We had a really good team and everyone was super-young at the time.
"It wouldn't have been fair to leave them. It's a super-special group, everyone works super-hard and it's starting to show now."
The Broncos can't keep all their stars, and Farnworth is a classic example of a player whose market worth has soared over the past two seasons, making a three-year offer from the Dolphins too good to refuse.
"The contract wasn't where I wanted it to be and there were a few things that didn't really favour me," Farnworth said in response to a question about his decision to leave Brisbane.
"The Dolphins was the best fit for me. I am pretty keen to join them next year and work under Wayne (Bennett). They have a really good side there as well.
"I am loving my time at the Broncos and hopefully we can leave with a special win in the grand final … but I'm not looking past this week."
The Broncos have not won a premiership since 2006, with Farnworth keen to be part of a magnificent seventh title for the club.
He watched the 2015 grand final - lost by the Broncos to North Queensland in golden point - at a mate's house in England after he had signed with Brisbane as a teenager.
"It was a special grand final and the Broncos were unlucky in the end. It was a classic game," he said.
"It would be massive to break the drought."
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