One word that perfectly describes former Germany and Bayern Munich goalkeeper Oliver Kahn is intense.
Most professional footballers hate losing but Kahn's competitiveness reached new levels.
He didn't care who he upset on his way to a phenomenal honours list that included eight Bundesliga titles, six DFB-Pokal trophies and the Champions League.
Football hasn't quite seen someone like Kahn since his retirement in 2008. Many centre-backs, prone to being shouted at by 'Der Titan', were probably relieved to hear that he'd hung up his gloves.
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Kahn suffered from burnout
However, his 'win at all costs' attitude had a pretty sad impact on Kahn. In a new documentary about Bayern Munich called 'FC Bayern - Behind the Legend', the former 'keeper reveals how years playing at the highest level led to him suffering with depression and burnout.
“Depression, burnout, those are also all things that somehow coincide,” Kahn said, per Bavarian Football Works.
“At the end of the 1990s, I was simply exhausted.”
Kahn was ruthless - even against kids
Kahn is 52 now and holds the position of CEO at Bayern.
For an example of his competitive spirit, we're going to tell you a crazy tale about the German icon that's told in 'Tor!', a book about the history of football in Germany.
Kahn was asked to partake in a penalty shootout against a group of nine-year-olds. It was all in aid of charity, and money was donated for every penalty that the young lads scored.
But Kahn couldn't allow himself to be beaten, even for charity.
"It was for an orphanage but Kahn stated that he simply couldn't be beaten," the story goes.
It's no wonder that goalkeepers are described as being insane.
Kahn, though, believes they all need to have a wild side in order to succeed.
He told the Bundesliga's website: "I often use my body language to show my team 'complete presence' - and to instil respect, or even better fear, in my opponents.
"Goalkeepers need an element of insanity. Who else would stand there and allow people to shoot balls at their face or stomach, and still think it's great?"
We're just thinking about those poor kids.