Dylan Hartley reckons England's Six Nations victory over Ireland can be traced back to recent heartbreaking defeats against New Zealand and France.
Head coach Stuart Lancaster described Saturday's 13-10 triumph at Twickenham as the most significant win of his two-year spell in charge.
The result created a four-way shootout for the title with two rounds remaining, Danny Care's 57th-minute try, converted by Owen Farrell, turning a 10-6 deficit into a 13-10 lead England never relinquished thanks to their courageous final-quarter defence.
England established leads against New Zealand in the autumn and France in this year's Six Nations opener, only to succumb to decisive late tries.
There were no lapses in concentration on Saturday, however, as a starting XV containing 422 more caps at 724 and with ranks stiffened by the presence of nine Lions was outwitted and outfought.
"There was a load of talk in the week about Ireland outnumbering us in caps and a lot of people were saying 'ooh, look out, they've got this and that'," Hartley said.
"It was good to concede points like we did against New Zealand and France, but this time to stay composed and actually close the game out.
"We showed experience beyond our years to close the game out and our defence was outstanding.
"When you talk about caps on paper, I don't think it's that important, as long as you learn the lessons from recent weeks, which I think we have.
"It shows how far we've come from the autumn, losing against the All Blacks and then losing to France.
"As long as we're learning lessons and improving, that's the main thing.
"The positive thing is that our Six Nations dream is still alive. It was nice to stop Ireland getting the Triple Crown."
The momentum shifted in Ireland's favour when Jamie Heaslip expertly sent Rob Kearney through a gap at the breakdown and he raced over the whitewash to create a 10-3 lead.
Displaying plenty of spirit, England clawed their way back into contention through the kicking of Farrell and Care's try, which was conjured by his Harlequins team-mates Chris Robshaw and Mike Brown.
Only three minutes remained when Gael Fickou crossed the line in Paris to break English hearts and Hartley admits it is an image that haunts them still.
"We were caught napping around the breakdown, it was myself and Joe Launchbury that Kearney went between," he said.
"But the way we closed that game out showed the spirit in the team.
"We learnt from the France game that it's about producing intensity for 80 minutes. You can't nap at all, especially when the game was on a fine line like it was against Ireland.
"One missed tackle could have been costly, so it's very pleasing that we held them out.
"It was after that France game, when you review a game, that you learn your lessons. It doesn't really have to be spoken about again.
"That fear of losing the game in the last three minutes is always there in the players' head. The defensive effort was huge."
Full-back Mike Brown was named man of the match for a second game in succession, but Joe Launchbury could have taken the award just as easily.
Launchbury was a Titan in defence and made 15 tackles, just one less than captain Chris Robshaw who topped the stats for either team, and finished the contest at blindside flanker.
"Joe had three turnovers at the breakdown. He's quiet and goes about his work. I thought he was fantastic," Hartley said.