But while Kearney has been not far short of sensational against Wales, Italy and France, Ireland have been much more hit and miss.
Declan Kidney's men showed glimpses of their potential in the last-gasp loss to Wales and the convincing second-half showing against Italy before coming within a whisker of securing just a second win in Paris in 30 years.
But rather than looking at three wins from three attempts and chasing a second Grand Slam in four seasons, Ireland have just one victory and a draw to their name despite having led the Welsh until the last play and built up a 17-6 half-time lead over the French.
And with the margins between success and failure so small at the top level, Kearney is urging his team-mates to find more metal strength and develop a greater belief in their own abilities.
"It all starts with mentality," said Kearney.
"If we have that inner desire and inner belief that we can beat anyone in the world, then we will.
"We're a good team. We have a lot of strong belief and we know what we can achieve. We know that on our day we can muscle up with some of the best teams in the world. And we did that against France.
"It's just that the margins are so small...I think we might have lacked that one or two percent of a killer instinct in us. These games are tiny margins and if we get another one percent of a killer instinct, we can close these games off.
"I think it's about winning and having enormous self-belief as well. The more games you win, the more momentum you build and the more confidence you feel."
A draw against the World Cup finalists at the Stade de France is no mean achievement but the manner of the result the Irish feeling like it was a point lost rather than one gained.
The chance to celebrate success in the French capital hasn't come around too often and Kearney insists the players weren't patting themselves on the back despite doing themselves proud in Paris.
"We still haven't won in Paris in so long. We came and we wanted to win," added Kearney.
"We knew we were good enough to win and we can't start taking this mindset that it was a good result, a good effort, that the Irish fought hard again, because we're coming second best and we're not going to be a competitive team that achieves if we take that attitude.
"So, I don't really buy that and I'd like to think that none of my team-mates do either."