Chris Coleman cited a difference of opinion with the Welsh hierarchy for his decision to leave Wales and become Sunderland's new manager.
After guiding Wales to the semi-finals of the European Championship last summer, Coleman stepped down from the post earlier this week after missing out on qualification for the World Cup.
That he should choose Sunderland, who sit bottom of the Championship table following relegation from the Premier League, came as a big surprise to many in football.
Talking to the Sunderland website, Coleman said: "Having achieved what we'd achieved, I thought to take it on to the next level I needed to work slightly differently. And the powers that be in Wales saw it differently to me.
"In my experience it was the right time for me to say, 'OK, that's as far as I'm going to take it'. Pretty quickly really the opportunity came about with Sunderland.
"I asked one or two people that I'm close to about it and they said, 'If there's any doubt in your mind, don't go to the stadium, don't go to the training ground, because you'll sign'. They said it's fantastic.
"So I didn't come (to the training ground), (chief executive) Martin (Bains) came to where I live and I agreed to join. Of course my first morning here today, absolutely amazing, the set-up's fantastic.
"I'm quite sure managers before me have said the same thing, but it really is all in place except what happens on the pitch and we've got to make sure we get that right."
Coleman is Sunderland's ninth manager in the last six seasons and replaces Simon Grayson, who was sacked at the end of last month.
The 47-year-old, who has signed a two-and-a-half-year deal, takes over a club in crisis, with Saturday's 2-2 draw against Millwall giving them an unwanted English record of 20 consecutive home games without a win.
Coleman led his first training session on Sunday morning and will be in charge of the side for the first time for Tuesday's trip to Aston Villa.
Coleman, whose previous club managerial experience came with Fulham, Real Sociedad, Coventry and Greek side AEL, accepts the task in front of him is huge, but believes the potential of Sunderland outweighs the negative of their current position.
He said: "Someone's going to turn this club around. Whether it's me or whether it's the next one, sooner or later this club will start climbing again, start playing in front of a full house again, get the city rocking and rolling. I want that to be me, of course.
"You can go through your career as a manager and never manage a big club. I always wanted to have that experience of managing a big club, and here I am.
"All right, we're bottom of the league. Deal with it, get on with it. It is going to be a big challenge and I haven't got a magic idea that's going to turn it around like (clicking your fingers).
"I'm going to need all the supporters, all the staff, the players, everybody to come with me. It's such a big club that, when we gather momentum, it's pretty hard to slow it down, but the start's always the toughest part.
"I'll find out pretty quickly I think who's really in and who's not, and whoever's not needs to go and play football somewhere else. It's a little bit daunting, but that keeps you on your toes."