Alun Wyn Jones admittted he feared he would never play for Wales again after his Twickenham sin bin.
And the Ospreys lock insists he is a lucky man to get another crack at Test level in Saturday's Six Nations showdown with Scotland in Cardiff.
Jones, 24, said: "It was one of the most stupid and idiotic acts I have ever done on a rugby field and I thought it would jeopardise my international career. You have to have that view when you make such a mistake because the opportunities to play Test rugby are few and far between.
"I am fortunate but I've been given this second opportunity now. I don't want to try too hard because that's when you make silly mistakes but I obviously want to put some wrongs right."
Wales assistant coach Shaun Edwards confronted the British Lions second-row star in the dressing room following the costly sin-binning and warned him never to repeat his actions.
But Kiwi coach Gatland believes the incident at HQ has been put firmly behind them. Gatland said: "It was dealt with straight away in the dressing room and is dead and buried.
"Everyone makes mistakes and I'm sure he and the other players will learn from it. Sometimes you get away with having 14 men but we didn't."
But Jones accepts the Welsh management were correct to single him out for punishment. He added: "Shaun and Warren were right with what they said. When Warren first came in he said he would be honest with the players. It is refreshing and I respect him for saying it.
"It's a cut-throat mentality we haven't had before and Gats has brought that off-field southern hemipshere cutting edge. Hopefully that will provide dividends for us."
Gatland has made just two changes for the clash at the Millennium Stadium with wing Leigh Halfpenny and line-out specialist Jonathan Thomas preferred to Tom James and Luke Charteris with fit-again prop Gethin Jenkins on the bench.
Gatland said: "Jonathan is experienced and will bring us some extra mobility while Leigh offers us an extra kicking option."
Wales: L Byrne; L Halfpenny, J Hook, J Roberts, S Williams; S Jones, G Cooper; P James, G Williams, A Jones, AW Jones, J Thomas, A Powell, R Jones (capt), M Williams
Replacements: G Jenkins, H Bennett, B Davies, S Warburton, R Rees, A Bishop, T Shanklin
Young referee Ben Breakspear is making rapid strides as a referee. In just over a year he has gone from officiating a college game to being a touchline official during last weekend's RBS 6 Nations clash between Wales and Ireland at Principality Stadium.
Grand Slams, Triple Crowns and British and Irish Lions tours - Sir Gareth Edwards did it all. But what are his favourite moments in what was an amazing career? WRU TV finds out - along with his favourite players of today in the third and final instalment of our series with the greatest rugby player ever.
JPR Williams, Gerald Davies and Mervyn Davies were among those in the Welsh ranks when Sir Gareth Edwards began his international career against France nearly 50 years ago, but who was the player who took the young scrum half under their wing?
Wales head coach Rob Howley and captain Alun Wyn Jones are expecting a physical battle against France on Saturday but both are hoping for another impact from the bench as the men in red chase a top-four world ranking.
It's nearly 50 years since the great Sir Gareth Edwards made his debut as a youngster for Wales against France in Stade Colombes. In the first of a series, WRU TV discovers he pocketed a 'special momento' from the game - something he still has today.
This week, Wales squad players Sam Warburton, Jonathan Davies and Ken Owens took time out to support Operation Net Safe, a joint initiative by the four Welsh police forces to tackle child sexual abuse. The forces are working with the Lucy Faithfull Foundation, the only UK-wide child protection charity dedicated solely to reducing the risk of children being sexually abused, on a campaign called Stop it Now!