Jack's legacy - Shockwaves from the Charlton era are still being felt by Ireland managers 30 years on
Sometimes there are landmarks of time and history which command passing attention - and then you hop back to the realities of today. There are other occasions when you confront not a slab of old memory but a living and unshakeable state of mind.
We probably need not tell Martin O'Neill this as he attempts to regain some momentum after the crushing denouement of his World Cup hopes, a blow that he must still feel in his bones when he recalls the cavernous creative gap Christian Eriksen and his Danish team-mates achieved in Dublin last November.
The landmark, which if he was to think of it too much might settle on his shoulders as an impossible burden, is Neckarstadion, Stuttgart, 30 years ago when Ireland celebrated their first presence in a major tournament with a European Championship victory over England.
But then it was so much more than a mere win over an historically formidable opponent at the highest level Irish football had ever reached, if we forget the Free State victories over Bulgaria and defeat to Holland amid the carriages and champagne picnics of the Paris Olympics 64 years earlier.
In the old stadium of Stuttgart - it now gleams with the wealth of Mercedes-Benz - it was an arrival, a new way of looking at yourself and believing in what you saw.
It was a bit rough at the edges, and not exactly suffused with the subtleties of a retired John Giles or a suspended Liam Brady, who would always have to fight for his green shirt despite the most extraordinary skill.
It was not so much in your face as your entrails, it was the self-assertion of a particularly strong and unadorned nature. It was, in short, Big Jack Charlton.
And, soon enough, nothing would ever be the same in Irish international football. No longer would small advances stir the Irish football soul.
Yes, there had always been heroic and brilliant figures in an Irish shirt. But the parts, however shining, never made a satisfactory whole.
It was no longer good enough to be colourful and sometimes gallant operators on the fringe of the international scene.
The taste of Irish pleasure in Stuttgart was intoxicating in a most civilised way and it was easy to gauge the depth of its source.
It was that sense that you can, after all those years in the margins, the days of having your heads patted for courage in defeat in the upper echelons of the game, make an impact in superior company.
Maybe it feels, suddenly, that you are attending the starry party not to carry a tray of drinks but to get to the heart of it, maybe even dance with the hostess.
True, England did not have the status of Charlton's victims of the previous year, Brazil, but that was a friendly.
It didn't have such a distinguished football man as Bobby Robson yanking at his hair on the touchline.
It didn't have Charlton exhorting his men with a passion as heightened as any he had displayed since sharing the World Cup final field with his brother Bobby 22 years earlier.
Houghton's early goal did for England, which was something to remember two years later when Robson's team rallied in the World Cup of Italy to force eventual champions Germany to a semi-final penalty shootout.
There were other achievements to take home to a nation grateful to finally see itself on a significant football map.
Ireland went home after the group action despite their triumph over England, but not before a draw with an impressive Soviet Union team and the holding of champions-elect Holland to just one goal, and that one coming in the 82nd minute.
Charlton went back to Dublin not so much the eccentric Englishman but as a man as good as some extremely forceful words.
Not granted the courtesy of an interview by the English FA after Don Revie donned a false beard and flew away for Arab gold, and Brian Clough was deemed far too explosive and wilful, nearly a decade later he told the FAI what he wanted to do for his own country.
It was to turn a national team into a tight, familiar and like-minded unit, the kind his mentor Alf Ramsey had made while winning the World Cup in 1966.
One of the more biting lessons was delivered by Ramsey when Charlton, nearing 30, was so thrilled by being selected ahead of young, and more naturally skilful rivals, almost light-headedly asked the manager why he had been chosen.
"Jack," said Ramsey, "you must understand that my job is not to pick necessarily the best players. Oh no, my job is to select players I believe will be best able to form an effective team. This job is about making a team and that's the only way we are going to win the World Cup."
Charlton did not win the World Cup for Ireland but he did the next best thing. He made the great tournament seem so much less an alien planet.
He made it accessible, an old fantasy made attainable and when in 1990 in Italy and America four years later you saw the happiness of Irish fans in the streets of Rome and New York, you knew that a great football life's work had been largely fulfilled.
He had done what he swore he would do back in his more frustrating days at Leeds United, when his passions and eccentricities provoked as much mockery and practical jokes as they did respect among some extremely hard-edged pros.
The manager Don Revie found himself wondering if the big and sometimes gawky defender really had the makings of an authentic pro.
Soon enough, though, he came to recognise that in a highly-strung, quick-fire personality there was a most powerful streak of natural-born leadership.
Jack Charlton loved the exhilaration of the open air, the shooting moors and the trout rivers but he also knew what it was to go down a coal mine shaft and this informed every long stride of his fight to make football his escape, his salvation.
It was such a force which took over Irish football in 1986 when the authorities, after weighing the impressive credentials of the late running-candidate Bob Paisley, decided that in Charlton they had not only a football manager of proven accomplishment but with a need to succeed entirely in his way and on his own terms.
No, he wasn't going to explore the bye-ways of Ireland for the skill of which so many native-bred players had displayed individually but never as a fully coherent or significantly progressive team.
No, he wasn't going to listen to the chidings of purist critics who said his pressing, long-ball game was a form of national betrayal.
He wanted fighters, winners and he would find many of them not in the home hearth but to wherever their Irish bloodlines had taken them. It was not novel strategy, but Charlton brought to it a special force which led directly to the emergence of full-blown Irish heroes like Ray Houghton from Glasgow and the almost definitive Liverpudlian John Aldridge.
Significantly, both came to their Irish glory by way of the football backwater of Oxford United.
The essential work had been done and now, 30 years on, the legacy is there to inspire - or haunt - all of Jack Charlton's successors.
It has been perilous, sometimes devastating work, but three of them, O'Neill, despite the Danish disaster, Mick McCarthy and Giovanni Trapattoni, have at times wrapped themselves in that Charlton tradition of believing that Ireland might just live, for a little while at least, amid the best of football.
O'Neill's Ireland beat Germany when it mattered and prised considerable glory from the 2016 European Championships.
McCarthy combined the daunting challenge of fighting a civil war with Roy Keane and taking the team to the round of 16 in the World Cup of 2002, where they lost honourably to the talents of Spain after taking them to penalty kicks.
Trapattoni might have carried Ireland to the 2010 World Cup in South Africa but for the cold-eyed cheating of the celebrated Thierry Henry and then recovered well enough to qualify for the European Championships of 2012.
Unfortunately, he was then required to watch his team subside, unstoppably, beneath the superior talent of Croatia, Italy, and champions Spain.
No, Charlton did not change, inexorably, a pattern he simply gave it a new dimension - and new possibilities.
Most of all, he created a level of expectancy about which Irish football had before never been permitted to dream.
This doesn't make O'Neill's job any easier over the next year or two. But then Charlton never said football came with any kind of guarantee.
Indeed, he estimated the effective life of a manager in one place at about five years.
He stayed another five with Ireland, not least because of the fishing, but then, as he once confided to his brother Bobby, it was so much more agreeable than going down a coal mine.