IT WAS August 2014 and Anthony Joshua was in a hurry to learn. Having drawn a line under a short but glittering amateur career with gold at the Olympics two years earlier, he had surged to 7-0 in the professional ranks. All of his fights, however, had been done and dusted before the bell sounded for the end of round two with his latest victim, Matt Skelton, vanquished within 5 minutes and 33 seconds.

So when he got the call to join Klitschko in his training camp in the Austrian Alps, he jumped at the chance. For the Ukrainian, Joshua’s presence at Stanglwirt that summer made a lasting impression.

“Obviously sometimes there are up to 15 sparring partners in every camp,” Klitschko says. “People are coming and going and some of them I don’t remember.

“But I remember Joshua – he impressed me with his attitude. He was very raw but he was the Olympic champion, he carried himself well, I liked his attitude.

“He was in the background and learning. Sometimes you need to be quiet and just watch. He was observing everything. That is unusual.

“I had Olympic champions and former world champions in my camp but his attitude was totally different. He was not trying to impress anybody. He backed off, he was sitting on the side, not talking too much. He was watching, learning, asking questions. He was very polite. He was different to the others.

“He didn’t see everything back then but he got to know where I train, how I train, the rules. He got the vibe.”

Anthony Joshua

Klitschko’s policy of inviting a wide range of sparring partners to his high-altitude retreat in the Tirol mountains has acted as a double-edged sword. Not only has he been able to get a wide range of good, solid work, but also take a look at the other runners and riders in the division from close quarters.

Even then the veteran might have known that his path would cross with Joshua’s at some point down the line, although he may not have expected to be the challenger when they did.

Now 90,000 people will cram inside Wembley on April 29 to see if the 41-year-old can reclaim two of the belts he lost when he was beaten by Tyson Fury in November 2015, which remains the last time he fought.

In 2014, when Joshua first arrived in Austria, Klitschko was preparing to face Kubrat Pulev, which, it could be argued, is the last time he looked anywhere near his best in the ring.

So what does he take from those sparring sessions nearly three years on?

“It’s an advantage on both sides,” Klitschko says. “He got a chance to look and be in the background of my training team, my camp. He hasn’t seen everything but he got to know a lot. I got to know him in the ring.

“Yes, he’s still raw. But I look at myself and I’m still raw.”

The defeat to Fury was the fourth in his 68 fights as a professional. Ross Puritty was the first man to beat him, when he stopped the rising, 24-0 star in the penultimate round of their 1998 clash, which remains the only time he has boxed in Ukraine as a pro. Klitschko was WBO champion five years later when Corrie Sanders stunned him with a second round stoppage. He lasted until the fifth 11 months later but Lamon Brewster still produced the same outcome, leaving questions marks over the younger Klitschko brother’s future in the sport.

However he steadily rebuilt under Emanuel Steward, who transformed him into one of history’s most dominant heavyweights. So how did the disappointment of that befuddling defeat to Fury, the first man to outpoint him, compare to the other three?

After a long sigh and an even longer pause, he said: “Please excuse me as this may sound arrogant but, for example, a parallel: Mount Everest. The highest mountain in the world.

“It’s been there for a long time and will be there for a long time. You can climb it during a certain period of time – during two weeks in April I believe. You can get to the top and say ‘I conquered Everest!’ Then you’ve got to run down because it’s going to take you down if you miss the time.

“A lot of people died there. Some made it, not many, but some made it back. But Mount Everest is still there. Is Mount Everest defeated? It’s still there and it’s going to take another life this April.”

He added: “You know what’s interesting to me, this is going to be my 69th fight. I’ve four defeats, but it’s always defeats people talk about. Why don’t we talk about something better! I haven’t been fighting all my life as a loser.”

But it is those defeats, Klitschko believes, which will give him the edge when he comes up against undefeated Joshua, who has gone from a 7-0 sparring partner to the 18-0 (18KOs) world heavyweight champion.

Wladimir Klitschko prepares for Anthony Joshua

“I’ve seen it many times,” Klitschko adds. “The more success they have, the cockier they’re getting, without knowing how deep water can get.

“All people in general act the same way. I’ve been there before, I totally get Anthony Joshua. I’ve seen how he breathes, how he acts and what he does.

“I believe that with failure and a lesson, it’s good before going to face this athletic, strong, young, ambitious man. I believe that my attitude would’ve been different if I was still a champion and AJ would have been the official challenger.

“In my mind, I’m coming after a defeat with a totally different attitude and totally different desire and obsession.

“You’re probably tired of hearing me say I’m obsessed, as you were tired of my style and you were tired of me always defending titles with complaints from the fans on how boring it was.

“But I’m going to be saying it until the 29th of April – so get used to it.”

Sky Sports Box Office will show Joshua v Klitschko exclusively live on 29 April. To book go to www.skysports.com/joshua