Moses Itauma was still a schoolboy when he would turn up at boxing gyms in his uniform and give seasoned professionals a hiding
On Saturday night at the O2 Arena, the 21-year-old was finally given an education, as the Briton ran out of gas and the granite experience of Filip Hrgovic carried the Croatian to the vacant IBF heavyweight title.
The referee waved off the fight as Itauma's corner threw in the towel in the ninth round. But for long spells, Itauma was the quicker, sharper and more assured fighter, repeatedly finding Hrgovic with the left hand and showing exactly why so many inside boxing believe he has the tools to reach the very top.
Yet what made the contest so compelling was the growing sense that, even while Itauma was winning rounds, he was drifting closer to defeat. His mouth opened in search of air and the spring disappeared from his legs. Hrgovic, hardened by the kind of difficult nights Itauma had never experienced, simply stayed there and waited for the younger man's body to betray him.
The sight afterwards was a sobering one as Itauma - who suffered a first defeat in his 15th pro fight - left the arena on a stretcher, before being taken to hospital.
"It's precautionary that he's gone to the hospital. That's what we always do to make sure because the most important thing is the boxer's health," promoter Frank Warren said.
"He's done something to his leg as well and he was quite tired. It was a high paced, fast fight for both the guys."
The remarkable night should not be remembered as the moment Itauma was exposed as incapable of operating at world level - his boxing showed the opposite. What it exposed was the difference between possessing world-level talent and having the conditioning, experience and ring craft required to manage a 12-round world-title fight.