The former midfielder spoke on Wednesday for the first time since taking up the role as the national team's assistant manager and pulled no punches.
His history with Ireland is pockmarked with controversy and clashes, his combative character leading to dramatic falling outs with those in the international set-up when he was a player.
The most notable came when he lashed out verbally at manager Mick McCarthy before quitting the team at the 2002 World Cup in Japan, but he was unrepentant as he gave his first official press conference.
Keane told Sky Sports News: "I am not here to try to change anyone's opinions about me or decisions I have made.
"I spent years trying to please everybody and, trust me, it's a waste of time and energy. You just have to do what you think is right.
"I like to set high standards - a lot of people seem to have an issue with that. The criticism I have faced over the last 15 or 20 years has been about me being very demanding and not settling for second best. I am certainly not going to apologise for that."
How well that goes down with fans remains to be seen and Keane accepts that, with new manager Martin O'Neill, he may have to win them over.
He went as far to concede that some supporters may never forgive him for walking out on Ireland as a player, but added: "I can't really worry too much about that. It's about the future, about today, trying to help Martin, the rest of the staff and the team.
"If we can do our job properly then hopefully people will get behind the team."
Keane took issue with Ireland's facilities and training before the 2002 World Cup and among the group of players he angered with his behaviour was Ray Houghton, who was a key figure in the recruitment process.
However, the new assistant insists there were no problems and it only took a couple of days for him to agree to the job and complete the deal. "Martin had already met with him and that was discussed," Keane said.
"Hopefully, one of my strong points is when I meet with people I have had disagreements with before, I am quite happy to move on pretty quickly.
"It was very straight forward with Ray Houghton. We wanted what was good for Irish football and Martin wanted me on board. The past is the past.
"I have got massive respect for Martin. We are certainly not buddies but hopefully we will work well together.
"We have come across each other a little bit covering a couple of matches but we are certainly not a pals' act. Martin is a very serious manager and I am hoping he is looking at me thinking I can be a decent coach or manager.
"It shows how strong Martin is, the fact he has brought me on board. Unfortunately, people might see me as a traitor or troublemaker of some sort but hopefully Martin's seen something in me which means I have got a lot to offer."
Those in the Ireland squad to face Latvia in Friday's friendly - the new management team's first game in charge - who have played alongside Keane in the past will know what to expect but others who are less familiar should not expect to be showered with high praise.
Faced with questions that he might have upset with his criticism of the team's poor performance at the last European Championships, he said: "There is an issue with lots of players in general who think they are better than they are.
"It is thrown around too quickly that players are world class or great players. I think it's taken too lightly."