You don’t feel it on the first day.

The first week will also be OK, buoyed by the good wishes and sympathy of friends and family. There’ll still be commercial engagements to complete; you may even have a few light sessions in the gym.

In the immediate aftermath of the fight, it hasn’t yet hit: ‘losing isn’t that bad. I thought I would feel worse.’

Yet eventually the world moves on to the next big event, the next big fight, and the silence you were dreading start to grow. Into this widening void the questions come:

Why did I lose?

Didn’t I want it enough?

Have I lost my edge?

Am I good enough to reach the top again?

Can I go through it all again, and if so, how can I do it better?

As brave and likeable as Anthony Joshua will appear in public, these questions will gnaw away at him. On the biggest stage, our national hero was found wanting. To many, it appeared he would rather be anywhere else than Madison Square Garden.

Before he can conquer the heavyweight division, Anthony Joshua will have to conquer the doubts that must increasingly dominate his thoughts.

Lance Armstrong popularised the idea that, ‘pain is temporary, quitting is forever.’

Anthony Joshua has to reverse this by quickly retesting his mettle for the fight. His team must recruit quality sparring partners, capable of testing him to his limits. The hope is that Joshua can recruit some tough, wily operators like Derek Chisora, Joseph Parker, or Carlos Takam for what will be the most important camp of his career.

Anthony Joshua need only look to the man he respects most – Muhammad Ali – who recruited sparring partners of the calibre of Larry Holmes, Roy Williams and Tim Witherspoon. These are the testing environments where you either sink or swim. The best continually seek out such environments, and thrive.

If the hunger and mettle within Anthony Joshua is real then the majority of correction is technical.

How can a man who trains so hard struggle to sustain his performance for the duration of a fight

In Andy Ruiz Jr, he fought a good heavyweight, but not a great heavyweight. Ruiz, blessed with handspeed, boxing intelligence and an iron will, remains a small man in the land of giants. Joshua has encountered such men many times before and dealt with them successfully. A return to the tactics that propelled his ascent to the top will serve him well.

There is value in a simpler fight plan that emphasises the jab, controlling ring territory and range. These are all skills he has mastered.

His trainer Robert McCracken has embodied that simple, stoic approach to the sport from his rise as a professional fighter in the 1990s to his success as a trainer of champions such as Howard Eastman and Carl Froch. Joshua remains in very capable hands.

Yet the conundrum of Joshua’s career remains: how a man who trains so hard and so often struggles to sustain his performance for the duration of a fight. Correcting these issues is a mixture of addressing Joshua’s base body composition and to an extent, his biochemistry.

The greatest value may be in reducing the mental load imposed on Joshua in fights. A relaxed fighter is a fit fighter. An often-forgotten truth in combat sports is that the mind surrenders before the body.

Despite the bright lights and flashbulbs, the ring is a very dark place when nothing you prepared for is working. You feel the pain yet do not see the source. Jolt after jolt, thud after thud, the attack is relentless and as the pressure builds you look for solutions in a mind that is careering directly into confusion. At that point, you doubt everything you think you know about boxing. Layers of training and conditioning fall away to reveal the raw novice.

At this point, no words of encouragement and no tactical advice can prevent the descent into an animalistic and instinctive beast. We saw this when Mike Tyson faced Evander Holyfield in their superfight and in every round after the fourth, we saw Joshua slowly unravel in the face of moderate pressure. McCracken, keenly aware that he had ‘lost’ his fighter to his fears and insecurities, was only left with the most basic instructions to bring his man back. With his confidence gone, his stamina followed rapidly after.

Ruiz was able to use his experience, honed over more than 100 amateur bouts, to anticipate, nullify and counter many of Joshua tried and tested tactics. Being figured out, so quickly and comprehensively, likely accelerated his rate of stamina depletion, as was seen between rounds three and seven.

Addressing this is a function of education and awareness. Trainers must ensure that, even in the darkest of trenches, their fighter can remain aware of his situation and understand the simplest solution to the challenges he faces. In this case, it will take some exceptional effort from the Joshua team to turn it around, but the good news is that it is not impossible.

There is a collective hope that Joshua redeems himself in the rematch

Questions remain, questions that can only be answered through hard graft. Can Anthony Joshua master the dark arts of defence before the rematch? These skills, the ability to block, slip and roll punches, individually and in sequence, are honed over years of trial and error, and very difficult to master in adulthood.

Will Anthony Joshua retain the goodwill of the British and wider boxing public? The reaction following the defeat has been overwhelmingly positive. There is a collective hope that Joshua redeems himself in the rematch. In doing so, he would ascend the ladder to boxing legend by overcoming what was a comprehensive loss and fuel that oft-told boxing tale of redemption.

The comeback is what makes boxing the greatest sport on earth. Anthony Joshua has been atop the boxing world for long enough to acquire the taste of success. Over the next six months, we will find out how driven Joshua is to return to the summit.

Terry Chapendama is a boxing trainer for both amateur and professional boxers. Follow him on Twitter and Instagram @highfieldboxing for advice on boxing-related matters.