Otto Rehhagel says he simply could not turn down Hertha Berlin when he was approached to become their new coach last week.
Rehhagel will take charge of the club on Monday with a brief to save the club from relegation.
His last job in the Bundesliga dates back 12 years, but the 73-year-old said he would never have accepted the job if he did not feel he was still able to make a difference.
"When Hertha need help, then I don't say no," he said. "I played my first ever Bundesliga game for Hertha on August 24, 1963 against Nurnberg.
"It finished 1-1 and I remember everything about it, I have the memory of an elephant. And now I am back and Hertha simply must remain in the Bundesliga."
Rehhagel has agreed to a contract until the end of the summer and, although nothing has actually been formally signed, he says he is a man of his word.
"I am here until the summer and then I finish with Berlin," he said. "But that doesn't mean that I will give up completely.
"My son Jens told me to accept the job because I won't be getting any more offers in a year or two so I gave them my word on Friday.
"I am fit, healthy and motivated. I can reschedule my personal business to the summer, but Hertha don't have that time.
"People are placing a lot of hope in me and I don't want to disappoint them."
Hertha have lost their last five Bundesliga games and were knocked out of the DFB-Pokal in a miserable start to 2012.
Rehhagel says discipline is the way to turn the corner and he is ready to restore law and order when he meets the team tomorrow.
"The good ship Hertha has not gone down yet," he told the Bild am Sonntag newspaper.
"But it does have a gaping hole. I am the commander from Monday and everybody will listen to me.
"I will always have the last word and I am there for Hertha day and night, and always on time.
"I am the forerunner and I expect order and discipline. I am a democratic dictator.
"If anybody does not respect the rules, then it is best they tell me that straight away. Professional footballers should go to church every day and thank the Lord because they have such a dream job."
