Pep Guardiola told Wednesday how a defeat against Chelsea prompted him to end his reign as Barcelona's most successful coach when he could no longer motivate the star players.
"If you can no longer reach your players, as a coach, the time has come to move on," Guardiola said in a rare opening up about his departure from the Spanish giants.
The current Bayern Munich maestro said that defeats are "moments of great sadness" like when "the floodlights suddenly go out."
"Seeing Barcelona go out against Chelsea in the Champions League semi final in 2012 was just such a moment.
"We were better than our opponents, but then conceded an unnecessary goal in the return leg, and before we knew it we were out of the competition.
"That was a really tough defeat for me. I felt like I could no longer reach my team," Guardiola said in an interview included in the Audi car company's annual report.
A 90th minute goal by Fernando Torres in the second leg at Barcelona earned a 3-2 aggregate win for Chelsea in the landmark semi-final.
Guardiola said the defeat prompted his decision to end his four years in charge of Barcelona during which they won 14 trophies including two Champions League titles. He was the first Barcelona coach to beat arch-rivals Real Madrid four times in a row.
Barcelona were "incredibly successful," he said. "Fourteen titles with the space of just four years meant it was the best period in the club's history.
"But it can also be a curse. I found it increasingly difficult to motivate both myself and my team."
He had won everything there as a player and a coach. "I noticed that the team was finding it increasingly difficult."
"Leading a team takes huge amounts of energy. In other words there are times when you need to recharge your batteries," added Guardiola, who took a sabbatical with his family in New York before joining Bayern in 2013.
Guardiola, 43, said he would not have been able to build the current European champion side in Munich without the Bosman ruling in 1995 that enable players to pick and choose their clubs across Europe.
But he added that there are also drawbacks to having a multinational team of soccer geniuses.
"With so many stars in the lineup, as we currently have at FC Bayern Munich or my former club in Barcelona, you may also come across situations where diversity can be destructive," he said.
The pressure for a starting place can be intolerable, he said.
"The ones left on the substitutes' bench are most likely to be the ones who aren't happy with my decision. And then there's the pressure from the press and the fans to select particular players.
"Whenever I left Lionel Messi on the bench for example, the whole of Barcelona was in uproar," Guardiola said.