New Bayern Munich boss Jupp Heynckes insists he has not lost touch with football during four years away from coaching.
The 72-year-old has been appointed as head coach until the end of the season following the sacking of Carlo Ancelotti last Thursday.
Heynckes has been away from the dugout since leaving Bayern at the end of the 2012-13 season, during which he steered the club to their first treble of Bundesliga, DFB-Pokal and Champions League wins.
But the former Real Madrid boss says he has kept up with developments in the European game and is fully prepared for what lies ahead between now and next May.
"I've watched the most recent developments, be they in the top foreign leagues with Real Madrid, Barcelona, Juventus or the Premier League. I've also been very busy with the Bundesliga," he told a news conference.
"There were several reasons [for my comeback]. There's the friendship with [president] Uli Hoeness and the contact with [chairman] Karl-Heinz Rummenigge, which has never been broken down the years.
"I also have a lot to thank Bayern for. They were the springboard to an international career, which then continued in Spain.
"I thought 2013 was the end of my coaching career. I've had several offers from top European clubs since the treble but they were never an option for me.
"Critics say I've been out the game for four years but football's not been re-invented. I've followed very closely.
"Age is a number and nothing more. Some feel old at 45. I've not changed. I feel young. I have the resting heart-rate of a 60-year-old!
"My job is to analyse the situation. Despite the difficult situation, I'm confident we will soon show a different face."
Heynckes also defended Ancelotti in the wake of his departure, insisting he deserves the highest regard for his record in football.
"The man won the Champions League three times. Every coach understands this situation," he said.
"I respect him very much and I would like to say this much: I've been through a similar situation in my career to the one Carlo is in now. I still have the highest opinion of him."
Hoeness said of Heynckes' comeback: "During various talks, we came to the conclusion that Jupp is the best solution. Personally, I'm very glad to have my close friend back at Bayern."
Rummenigge, who described Heynckes as "an absolute master of his profession", added that talks will be held with previous interim boss Willy Sagnol over his future.
"I told him he would not be in Jupp's coaching team. However, we've arranged an appointment for this week in which we'll clarify his possible future within our club," he said.