Wladimir Klitschko revealed that he needed the loss against Tyson Fury to motivate himself to get better.
The Ukrainian lost his WBA, IBF and WBO titles in a unanimous points decision in Dusseldorf in November.
“Losing feels good,” the 40-year-old told the BBC.
“I’m glad that my hand was not raised that night. Failure is not an option unless it is the only way to get better – and I had to get better. I needed a push to get better and I got it. I feel it.
“I didn’t show my full potential in the fight. Physically, I was in one of my best shapes, but mentally I wasn’t there, not present in the ring.”
Before the Fury fight, Klitschko had just three losses to his name along with 64 wins, 53 of them by knockout. In fact, you had to scroll down to 2004 to find his last defeat.
“After a while, you get used to defending and not conquering the man in front of you,” said ‘Dr Steelhammer’, who claimed he is out for revenge when the pair meet on July in Manchester.
“It will be different on 9 July. It’s not a rematch, it’s revenge. If you want to destroy a person, give him five years of success. I had no failures for 11 and a half years.
“After a while it’s OK to make a mistake and I made a mistake against Fury. I want to make that clear in my revenge and it is what I’m looking forward to.”
After so many years at the top of the heavyweight division, there were rumours after the shock loss that Klitschko could finally hang up the gloves.
But the former champion shrugged off the negativity and activated the rematch clause in his contract.
“I got over it,” he said of the loss.
“I was suffering for three days after, then I shook it off. Any rumours of retiring were not true. Three days after the fight I called and executed the option of the contract. That was it.”