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
After two years in the international wilderness, Adi Taviner is hoping to make up for lost time when she takes part in her second Women's Rugby World Cup which kicks off in Paris next Friday where Wales take on hosts, France.
The WRU's Women and Girls legacy events - #TRY OUR GAME have proved popular this week with current players and newcomers to the game learning new skills and picking up tips from national squad players.
We caught up with Shona and Ellie from the Wales women team ahead of the start of the Women's Rugby World Cup in Paris next month at a recent women's training session to encourage and promote more women and girls to try their hand at rugby. #tryourgame
The Women's Rugby World Cup warm-up clash between Wales and USA proved bittersweet for centre Elen Evans. Despite being one of the star performers on the day on her 50th Test appearance, USA edged home 10-7 at Cross Keys.
Wales completed their Junior World Championship campaign with a victory over Samoa. Team manager Mark Taylor and No 8 James Benjamin reflect on a tournament which saw Wales win three games and lose two.