SPIEGEL: Mr. Kahn, the one word that most aptly describes your career is insanity. One of your most famous insane moments happened during a 1999 match against Borussia Dortmund, when you almost bit the other team's forward, Heiko Herrlich, in the neck and almost delivered a Kung Fu kick to his fellow player, Stéphane Chapuisat. What's your take on these incidents, now that you have the wisdom of age?

Oliver Kahn: I'm reminded of those scenes almost monthly on some TV program or another. It just happened to be a highly emotional match, in which I truly overstepped the mark. But it was in fact harmless, because nothing actually happened. I would certainly not have bitten Heiko Herrlich, and I was three meters away from Chapuisat.

SPIEGEL: But you lost control.

Kahn: It looked pretty wild, but I was actually in control of myself. I've never really injured anyone throughout my career. It's part of my game to occasionally send a message, one that may be unpopular to the outside world, but can be important for the team. I was extremely annoyed during that 1999 match in Dortmund. We had gone through a long series of matches without conceding any goals, and I had just returned from an international match and had a huge bruise on my left thigh. All of these things can make a player aggressive. We conceded a goal right away, and I thought to myself: That does it!

SPIEGEL: Everyone thought: now Kahn has really lost it.

Kahn: That really surprised me. I thought to myself: They don't know me, otherwise they would see things differently. I always know how far I can go before I get kicked off the field. It was obvious to me that I couldn't actually kick or bite the other players. All I could do was make it seem that way.

SPIEGEL: It was a tightrope walk. But in the 20 years of your career, weren't you really close to insanity at times?

Kahn: Goalkeepers need an element of insanity. Who else would stand there and allow people to shoot balls at his face or abdomen, and still think it's great? You throw yourself at the feet of the other team's strikers, you give it your all, and of course somewhere in your subconscious you know that there are healthier things to do.

SPIEGEL: During your time in Karlsruhe, you once said that your rival is your enemy. Isn't that also a little crazy?

Kahn: I grew up in an era when "Dallas" and "Dynasty" were on TV and movies like "Rambo," "Rocky" and "Wall Street" were playing in the cinemas. The message was clear: If you work hard you'll make something of yourself, and anyone who tries to stand in your way is your enemy. Those were my infantile attempts to motivate myself. I can only smile about it today. But I guess that was just the 80s.

SPIEGEL: But the 1980s were also the decade of hedonism. Did you miss out on that part?

Kahn: It took me a long time to realize that football isn't martyrdom, but a game that's enjoyable, and one in which getting better at it is supposed to be fun. Perhaps it would have been better if I had understood this as a young man. But that realization didn't happen until later in my career. Besides, I am firmly convinced that you shouldn't necessarily emphasize hedonism, especially at the beginning of a career, but should instead focus entirely on performance.

SPIEGEL: How does one get out of this martyrdom?

Kahn: By no longer being willing to be constantly exhausted and to live in a tunnel that consists of nothing but football. When you have a child, football becomes relative. When you get involved in the problems of young people using drugs, as I have, and you get to know their stories, football becomes relative. And when you begin to share the worries and problems of friends, football becomes relative. But when I was between 20 and 30, my life revolved almost entirely around my job.

SPIEGEL: And then the system fell apart?

Kahn: I dealt with football every day, and every day I practiced longer and harder than everyone else, used every opportunity to think about how I could improve. I was so obsessed with football that you could say I was taking the goal home with me at night. And then one day the system fell apart.

SPIEGEL: And that was when your partying phase began. You wore designer T-shirts and spent your nights hanging out at the P1, and your love life was all over the tabloids.

Kahn: Transitional phase. That's what I'd call it.

SPIEGEL: Okay, transitional phase.

Kahn: The system shifted from one extreme to another. You try to make things right, but instead of doing it slowly and cautiously you want everything to happen right away.

SPIEGEL: At least you could have tried to keep the tabloids out of your fast-paced life.

Kahn: That's easier said than done. I'm not the kind of person who seeks the tabloids' attention and deliberately lives his life in that context. Not in the least. At the time, I tried to change my life and break out of my routine. But that turned into something I didn't like at all. I have always seen myself as an athlete. Of course, I made the mistake of unintentionally opening the door to my private life by just a crack. I wouldn't do the same thing again. It has to be accepted that my private life is private, and if that isn't the case, I have to do something about it. At some point I found the right balance for myself. But it's hard work, and no one gives you a free ride.

SPIEGEL: Wasn't this transitional phase also a reaction to the final of the 2002 World Cup, when the ball slipped out of your hand and Ronaldo scored?

Kahn: Many people have said: You should be happy that you didn't win the World Cup that year.

SPIEGEL: Do you see it that way?

Kahn: Of course not. I would love to have won the World Cup. But there are people who say: You were in a sort of tunnel at the time. Who knows where it would have taken you, if it had ended up bringing you success. The problem with the system I was living in was that it was exhausting. Being the world champion would have meant that everything was the way it should have been. But it wasn't. The mistake during the final was meant to show me that something wasn't right about my path in life, that a few small things had to be changed. And when I made those changes after the transitional phase, things improved for me.

SPIEGEL: The general view is that Oliver Kahn was trying to make up for his mistake, at the 2006 World Cup in his own country, by winning the championship that year. But then Klinsmann spoiled it for him. The next disaster.

Kahn: I thought: Hey, this is it, you'll do it in 2006. But then along came that Klinsmann system, and people had other ideas. In retrospect, sitting on the bench during the World Cup was very important for my life, perhaps even more important than playing. As far as I was concerned, it would only have been worthwhile if we had in fact become the world champions. And I don't know whether we would have made it with me on the field.

SPIEGEL: But you do think it's possible?

Kahn: I don't know. I think it's a little unfair and hypothetical to speculate about that now.

SPIEGEL: Do you remember how you felt when you left the Munich hotel that day, when Jürgen Klinsmann ended an almost two-year rivalry between goalkeepers by putting Jens Lehmann in the top spot?

Kahn: It was a real slap in the face, although I wasn't exactly naïve. It had been clear for a long time how the whole thing would end.

SPIEGEL: You believe that you never really stood a chance?

Kahn: Those are your words.

SPIEGEL: Hmm.

Kahn: Of course, I asked myself a few questions. Don't Klinsmann and Lehmann use the same advisor? Haven't (national team manager, Oliver) Bierhoff and Lehmann known each other since they were kids? Is it a coincidence that their wives are friends? Perhaps those two years could have been put to better use, or at least structured differently.

SPIEGEL: Did you ever discuss Klinsmann's decision with him at a later point?

Kahn: No.

SPIEGEL: Can you forgive Klinsmann?

Kahn: Forgive? I've never really seen myself in the role of the victim. Why forgive? I'm actually grateful to him.

SPIEGEL: What for?

Kahn: I learned a lot in 2006. After defeats, I ask myself: What can I do differently? How can I continue to grow? After the 2006 World Cup, I knew that you don't always need success, success, success on the pitch. The realization that you're not always standing down there on the field merely to win, to be successful, was very liberating. One can be successful by helping the team, the other players. All of a sudden I felt the kind of empathy for people that I hadn't felt before.

SPIEGEL: Because you shook hands with Jens Lehmann before the penalty shoot-out against Argentina?

Kahn: Before that, I would never have thought I was capable of sitting on the bench as the number two man. And it showed me that you can really achieve everything in life, even the unthinkable, as long as you're willing to work on yourself a little bit. Suddenly it was very easy and was the most normal thing in the world. Sometimes I ask myself why it seemed so inconceivable to me before then. Why? Is the ego so dominant after all? It was an incredibly important experience in my life.

SPIEGEL: Were you aware of the enormous symbolic effect of the gesture?

Kahn: I was really shocked when the scene was later shown on the screen in the Olympic Stadium. All of a sudden there was this huge applause in the stands. It was a moment that was much bigger than all the vanities or egomaniac behavior.

SPIEGEL: And yet are you still happy that you'll be gone when Klinsmann takes over as trainer at Bayern Munich?

Kahn: I see it from a purely professional point of view. I wouldn't have any problems with that.

SPIEGEL: On May 17, the day of your last Bundesliga match, your 557th, your new book will be released. The title is "I." Another insanity.

Kahn: The title is a provocation. Many will say: "There goes Kahn on another one of his ego trips." But that's not the point of the book at all. The subtitle is: "Success Comes from Within." Everyone who deals with success has to deal with himself. That's where the word "I" comes in.

SPIEGEL: But the book also reads as if you had joined the ranks of the self-help authors.

Kahn: I don't believe that the reader gets the feeling that the author is trying to tell him how to live his life. I just want to motivate.

SPIEGEL: But you do want to tell the reader what's needed for success?

Kahn: There are characteristics that you need to be successful. Of course, success is a relative term. It can be something completely different from winning the German championship eight times or making millions. The goalkeeper plays in a psychological position, and he's dealing with mental things. I wanted to describe the things I've done wrong and, most of all, what I've done right, so that other people, including those in other professions, could learn from my experiences.

SPIEGEL: Why didn't you write an autobiography?

Kahn: Because I think it would be odd for someone who isn't even 40 yet. Autobiographies remind me of someone like (former German Chancellor) Helmut Kohl, and other great, older figures.

SPIEGEL: Did you have a co-author?

Kahn: I have been working with a coach for four years. It was helpful for me to process all the things with which you are confronted in the business of professional sports. Much of what I wrote in my book is what I learned during the coaching process. The coach also helped me organize my thoughts and put them together in the form of the book.

SPIEGEL: Writing drives many a professional author to the brink of insanity.

Kahn: I'm familiar with that feeling myself. There were many times when I thought I should just throw out everything I'd written. But I kept going nonetheless.

SPIEGEL: You call it coaching. Could it also be called therapy?

Kahn: No, there's a huge difference. Coaching has nothing to do with psychological problems or illness.

SPIEGEL: You quote Aristotle and Kant. Are you trying to show that football players are smarter than many people think?

Kahn: Of course I'm familiar with the clichés about football players, but I'm not the type who spends his free time in training camp playing with his Playstation or playing cards on trips. The other players thought it was odd: There he is, reading again. There are certainly more types than the cliché suggests.

SPIEGEL: You also write about how to be successful throughout life. What's the next success on your agenda?

Kahn: I want to successfully make the transition from a life in professional sports to another life, without running into major upheavals.

SPIEGEL: Are you afraid of a life without football?

Kahn: It's the attempt to let yourself go, to seek emptiness and boredom. I don't know what's coming next. I could say something clever, but this is something you have to experience yourself. I respect the fact that I am suddenly pull the plug, but don't worry.

SPIEGEL: Oliver Kahn, the man who never stops, the titan, is now seeking emptiness and nothingness. Now that sounds like an interesting experiment.

Kahn: Six months ago, for example, I thought that I wanted to distance myself from football altogether. The closer I come to the end, the more uncertain I become. Who knows, maybe I'll be getting on my own nerves after only three weeks.

SPIEGEL: Your life isn't exactly going to be completely empty. You plan to be a commentator on the German national team's games on the ZDF network starting in September. Sounds like the typical career of a former player. Can't you think of something more unique?

Kahn: I do have a number of things planned. It isn't all that time-consuming.

SPIEGEL: What else does the future hold for you? Trainer, manager, president?

Kahn: On the one hand I would like to do something with football at some stage. For instance, we're prepared a project in Asia called "Oliver Kahn searches for the super goalkeeper," which could be implemented in many Asian countries. On the other hand, something new would appeal to me. Maybe start a company.

SPIEGEL: And one day you'll be the successor of Uli Hoeness (Bayern Munich manager)?

Kahn: That would be an option, but certainly not in the short term.

SPIEGEL: What will you miss?

Kahn: The experience of being part of the team. Otherwise nothing.

SPIEGEL: Not the fame?

Kahn: It was nice to have it. But the package insert listing all the side effects is long.

SPIEGEL: What are they?

Kahn: The risk of being unhappy. The mistrust that constantly grows. The public that you can't escape. The loss of matter-of-fact things. You can lose a lot as a celebrity.

 SPIEGEL: You write about three selves in your book: the private self, the self as a product and the competitive self. What exactly are you going to do with this competitive self without a competition?

Kahn: When I'm invited someplace, I certainly won't be running through a hotel lobby with my foot stretched out or beating my fellow player with my clubs on the golf course.

SPIEGEL: You talk about a second life that's about to begin. Does that term even make sense?

Kahn: You have a good point. Is it really a second life? That's probably slightly exaggerated.

SPIEGEL: Are you happy that it'll be over in a week?

Kahn: Yes.

SPIEGEL: Does it hurt that you weren't able to win the UEFA Cup first? And conceded four goals to St. Petersburg in the semi-final?

Kahn: It was certainly a shame at that moment, but it doesn't matter much to me anymore. I'm more than pleased and grateful for winning the Double.

SPIEGEL: Are you afraid of your own emotions, of tears, on May 17?

Kahn: No, then I'll just cry. What's the problem?

SPIEGEL: Mr. Kahn, thank you for this interview.

Interview conducted by Lothar Gorris and Dirk Kurbjuweit