O'Driscoll had featured in the first two tests - the 23-21 victory in Brisbane and the 16-15 defeat in Melbourne - but was replaced for the decider in Sydney that saw his team-mates deliver a 41-16 win for a historic series triumph.
For O'Driscoll, the decision was made more galling because he had looked upon the series as an opportunity for a glorious swansong to his fourth Lions tour.
Before the start of the season, O'Driscoll said in an interview: "Is he on my Christmas card list? Unlikely."
The 35-year-old eventually tried to ease the situation towards his former Ireland coach by jokingly handing him a Christmas card at a Downing Street reception for the Lions.
Gatland has also attempted to defuse the situation by appearing on Ireland's popular TV programme - The Late Late Show - to explain himself.
Gatland added: "A lot of people tried to make a big thing about the Irish situation. At the end of the day I made - or we made as coaches - what we felt was the right decision. A lot of people tried to insinuate it was an anti-Irish thing, but I am incredibly indebted to the opportunities that Ireland gave me in my rugby career in terms of starting off in club rugby with Galwegians, coaching Connacht, and having a chance as a 34-year-old to be an inter-national coach.
"I am really looking forward to going back. It will put an extra twist on the game as people will try and make something out of it as they always do."
Gatland hopes by the time Wales reach Dublin, after their first game on Saturday week against Italy, they will have a fit captain in Sam Warburton. He has not played since Wales lost to Australia in November because of a shoulder injury.
Though Warburton said a final decision would not be made until next week, he seems almost certain to miss the Italy game.
Gatland strongly believes his Wales squad will be able to ignore the rugby politics which could dominate the off-field talk.
"We've said whatever the political issues are those are things us players and coaches can't affect."
Wales are attempting to become the first team to win three successive 6 Nations titles, a feat which would match the deeds of Welsh teams in the 1970s.
Gatland said his players had endured having that success"rammed down their throat year after year after year".
He added: "That's 40-odd years ago now. It's about time we had a new era of success. Hopefully, this is the middle period of a golden era in Welsh rugby."
Wales will face an Ireland team still recovering from that last-ditch, 22-20 defeat by the All Blacks in November.
Irish coach Joe Schmidt, who will be involved in his first 6 Nations campaign, said he had taken time to get over the defeat.
"It's been a bit of a recurring nightmare for me, however, because it's the first time I've had this experience as a national coach.
"In the past I have always had the next week to get a game out of my system, and my team too."
- Daily Mail
