Former Ireland Rugby international Keith Earls has said that the Irish team "failed" at the World Cup but nevertheless they had "inspired a nation".

The 36-year-old's final match in an Ireland jersey was Ireland's World Cup quarter-final defeat to New Zealand on 14 October.

In the first interview since his retirement, Earls said the team had "truly, truly believed" that they could have won the World Cup as a result of "the culture we had created and what we had done over the three years, some of the games we had won, some of the teams we had beat."

"We had this motto for three years, it was to inspire a nation by bringing a cup home to get an open top bus down O'Connell Street in Dublin... and ultimately, you ask any of the lads, and its harsh, but we failed, and (we) understand that even though we failed we did inspire the nation," he told Patrick Kielty on The Late Late Show.

"We wanted to go out and win it, it wasn't a cockiness from us, but as Irish teams in the past, we would have been scared to kind of say it, whereas we truly, truly believed it this time," he said.

"We had the right ingredients, but that's sport, if you have a small amount of poor discipline against a team like New Zealand then they'll punish you," he added.

Earls described the atmosphere in the dressing room after the match as "an emotional wreck".

Coach "Andy (Farrell) stood up and he spoke about myself and Johnny and I think everyone forgets about our good manager Mick Kearney, the three of us were moving on and we had some special times together, myself, Johnny and even Mick for over a decade and it was just gone in 80 minutes," he said.

"It was quite emotional and there were lots of tears from a bunch of macho mean," he added.

"It's still hurting, it's still raw about what could have been, but I've learned to accept it ... there's nothing we can do about it now. We've just got to learn and hopefully the lads move on and do something no other Irish team has done in four years' time."

A native of Moyross in Co Limerick, the rugby player said that he is proud of all that he has achieved.

Earls said: "I'm proud that I've stuck at it... even when I was younger, where I've come from, I wasn't supposed to make it.

"I'm happy. I went against the odds of where I've come from, the odds of myself, my own struggles," adding that he has gone on to have "a good life and a good career" with more opportunities ahead.

Earls has previously spoken and written about dealing with his bipolar disorder, including in his book 'Fight of Flight'.

Speaking on the show, Earls said: "I am proud of the book and the impact it's had".

"I'm in a good place, that's all I can say, it's going to be constant work. I think it is for everyone, no one's ever going to figure it out, but it's all part of the journey really, that's what's most important," he added.

He told Kielty about working towards being "medication free" this year.

"I know it's very important for people to take medication, but I didn't want to rely on it, and I felt if I kept working hard and understanding myself and trying to figure it out... I wanted to be medication free," he said.

"I went on my journey and I don't want to say what I've done because other people might try and do it, and what works for me isn't going to work for everyone, but the main thing is go and talk (to a professional), and then go and figure out and start doing things that you want to do and what makes you happy, and that's exactly what I've done," Earls said.