Almost from the day he learned to walk, the Australian was obsessed with the minutiae of machinery and the nth degree of detail in design. It propelled him to three F1 world titles and much of what he achieved in his domain happened through an unprecedented input from this extraordinary human being.
It simply couldn't happen today, in the modern, cast-of-thousands crew who inhabit the grand prix milieu, that a rugged individualist such as Brabham could become king of the world in a car he designed himself. At 12, he was driving trucks in his father's grocery business; at 15, he was combining a job at a local garage with an evening course in mechanical engineering. At 18, despite his determination to become a pilot during the Second World War, his expertise in knowing how engines ticked meant he was otherwise employed as a flight mechanic.
Brabham loved driving and travelling at speed - it would be difficult to thrive in F1 without possessing these qualities - but he was equally fascinated with the whys, wherefores and whatevers of speed and motors. In many respects, it defined his whole life.
In the early days, the notion of racing cars at full pelt didn't offer any appeal - he was convinced the drivers were "all lunatics" - and he didn't so much advance into the sport as inch towards the cockpit.
Once there, his destiny was sealed. First in his native country, then in the wider world, Brabham gradually proved he was one of the masters of his vocation. But none of it transpired quickly. Indeed, his story should provide inspiration for late developers everywhere. Brabham didn't even arrive in Europe until he was nearly 30, and, initially at least, he was not regarded as one of the greats. Yet, as the months passed and he tinkered with different parts of the car and brought his own expertise to bear, it was noticeable how dramatically the Cooper team's fortunes improved. He himself refused to take all the credit for this development - "there were plenty of us working very hard to make things better," he said later - but the results spoke for themselves.
But he was 33 by the stage he attained his maiden Grand Prix victory in 1959 at Monaco and there was little of the swagger or bravado from Brabham which oozed from many of his rivals. Some said he hated seeing lovingly-crafted vehicles being destroyed; others argued that he had never forgotten the grievous loss of life in the war. The truth probably lay somewhere in the middle, because Jack was no stereotypical Aussie larrikin. On the contrary, he was methodical, self-absorbed to the point where he spent hours in garages on his own, refining the car he was taking to the track the following day.
It was a modus operandi that worked spectacularly for him, but created the impression of an enigma. At any rate, he triumphed at the climax of a spectacular world championship battle in 1959 and repeated the feat in 1960 and despite some rather sniffy assessments of his abilities, nobody flukes two global titles in any sport. Yes, Brabham had a low-key presence, and could never fathom why so many of his adversaries thought it was amusing to mix Champagne and cocktail waitresses with cars. But the critic who declared "his titles owed more to stealth than skill" was talking through his hat.
As he passed 35, one might have thought he would bow out gracefully and become an engineer. Instead, Brabham established his own marque with compatriot, Ron Tauranac, and became the first - and still only - man to wear the F1 crown driving one of his own vehicles in 1966. He was 40, which makes it one of the greatest feats in grand prix history, and yet there was still a reluctance by many to accord him the praise he deserved.
It didn't really bother him. The records were there in black and white and he could do without any great fuss. But Jack Brabham was a very special individual, all the same.