While distance lends perspective, it can also lead to the growth of myths - and the 25 years since Western Samoa beat Wales in the 1991 World Cup in Cardiff seem to have done more of the latter.
It was much invoked last year when Japan beat South Africa in the World Cup. There are clear parallels, since both involve an emerging rugby nation defeating an established one. And there's no doubt Samoa's achievement was momentous.
They were the 1991 tournament's only rookies, playing in their first World Cup finals match, and on their opponent's home ground. But was it, as Japan's feat undoubtedly was, a shock ?
Hardly so when one considers Wales at the time. Defeat by a previously unconsidered group of islanders was not even a low point.
That had come earlier in the year when 134 points were conceded over two weekends - 71 to New South Wales and 63 to Australia - and Welsh players had brawled among themselves at the dinner following the international.
Those punch-ups were the culmination of the ill-feeling which had built over coach Ron Waldron's en masse importation of both the methods and personnel which had made his Neath team hugely successful at club level.
Hugely effective in driving club players into the errors which come when they have been run to exhaustion, they were predictably much less successful against the fitter, more skillful adversaries encountered at international level.
Waldron had resigned, citing ill-health, so Wales went into the 1991 World Cup (as it would again in 1995) with a new coach - Alan Davies, who came from Ynysybwl via a highly successful stint in England with the upwardly mobile Nottingham club.
There was also a new captain. Full-back Paul Thorburn had quit at the end of the Australian tour and was replaced by wing Ieuan Evans. They had had only one match to prepare, played against France on 4th September at the National Stadium to mark the installation of floodlights.
Wales lost 22-9 in a match probably now most remembered by Luc Evans, who enjoyed one of the shortest of all Welsh international careers as a replacement for captain Ieuan. But Wales still were not too concerned about the Samoans.
As scrum-half Robert Jones recalled "We had played them a couple of times before, beating them without too much trouble."
In an age where rugby news travelled infinitely less quickly than it does now, and even the most famed visitors arrived with a certain air of mystery, they had little idea what was about to hit them. Peter Fatialofa did.
The Samoan captain had told his team 'The Welsh have never seen tackling like Samoan tackling. We'll smash the crap out of them."
A prop who would have played for the All Blacks if the selectors had been more convinced by his scrummaging, Fatialofa ran a piano-moving business in Auckland and certainly gave the impression that he was capable of lifting a baby grand one-handed.
A stalwart of the Auckland team which was putting together an unprecedented seven-year run in the Ranfurly Shield, he had persuaded colleagues with island heritage to join him in playing for Samoa.
This made the 1991 team a very different proposition to those beaten in 1986 and 1988, which had conformed to the islander stereotype of being terrific with the ball in hand but less convincing in tighter and more technical aspects.
Frank Bunce, one of those recruits, recalled: "We never had much as a team. We didn't have any money or any gear. We just had a lot of belief, support, faith and talent."
They also launched the debate, which lasts to this day, about New Zealand's relationship with the islands.
In this the refusal of kiwi critics to acknowledge that New Zealand rugby has played fast and loose with islander talent has its mirror image in a British inability to recognise that, like the large number of Jamaican-descended men who have played football for England, the phenomenon also reflects population flows which have nothing to do with rugby.
The number of male Samoans living in Auckland is greater than the entire population of Samoa. Bunce, who would shortly afterwards begin a highly distinguished All Black career, is a case in point.
His qualification to play for New Zealand, where he was born, raised and educated, was impeccable. But his island heritage was from Niue, where his great uncle, Sir Robert Rex, was Prime Minister. As a descendant of George III - hence the Rex surname - Bunce arguably also qualified to play for, or even rule, England.
On a grey autumnal Sunday afternoon it was clear from the start that this tough, battle hardened and highly motivated group - also including back rower Pat Lam and wing Brian Lima - were more than capable of coping with a Wales team still recuperating from the traumas of Australia and fielding the brilliant but half-fit Mark Ring at outside-half.
"That was some of the hardest tackling I have ever seen", reflected coach Davies afterwards. The 20 year old Scott Gibbs, not yet the formidably powerful figure he became, came in for a ferocious battering by Bunce. Full-back Tony Clement had a bruise extending from the top of his leg to his ribcage.
"We never got into our stride", recalled Robert Jones. Yet the decisive moment of the match would not have been allowed under modern TMO rules. It came directly after half-time, with the score at 3-3.
In Jones's words :"I touched the ball down behind the line, getting my body right over the ball. A Samoan came in straight afterwards and touched down and the French referee, who was a fair way behind play, gave the try.
I know for a fact that I touched down first, and the television pictures backed me up." Wales battled on, scoring tries through their wings, Arthur Emyr and Ieuan Evans. But they never really recovered from that early second-half score, awarded by referee Patrick Robin to centre To'a Vaega.
A second try from back rower Sila Vaifale and eight points from the boot of scrum-half Matthew Vaea sealed a 16-13 win for the Samoans. At one level Wales had been, as the Telegraph's John Mason wrote 'hellishly unlucky'.
But there was little of the anger which has accompanied some other contentious Wales defeats.
As well as recognition of what it meant to Samoa, there was also acceptance, as the following season's Welsh Brewers Rugby Annual for Wales would put it, that 'the better team won'. It is hard to summon up much sense of injustice when that happens.
Yet the implications for Wales, with Australia to come in their group, were stark. Argentina were beaten 16-7 to keep hope alive, but the Wallabies, en route to the trophy, ejected Wales from the tournament - and into the qualifying competition for 1995 - with crushing efficiency.
That a 36-3 defeat in which Wales lost the lines-out by 28-2 could be correctly described as an improvement shows how low they had fallen a few months earlier. Samoa went on to show their defeat of Wales was no fluke.
On a Pontypool afternoon so wet that it was possible to believe a tide might start coming down the slope they held the Australians to 9-3 in one of the lowest scoring World Cup matches of all time, then sealed their quarter-final place by beating Argentina 35-12 at Pontypridd.
The end came in the quarter-final at Murrayfield when they ran into a tough, accomplished Scottish team on the trail of what remains to this day their best shot at reaching the final.
The Scots won 28-6 and their scrum-half Gary Armstrong recalled 'a superb game to play' in which 'our pack played some of the best rugby I have ever seen.' Samoa were given a standing ovation by the Murrayfield crowd.
Bunce did not play for them again, but Lima would still be there in 2007, four World Cups on. Fatialofa died early, suddenly and much mourned in 2013. They have qualified for every World Cup since, making the quarter-finals again in 1995 and the preliminary playoff stage in 1999, but have not made it out of their pool this century.
A tipping point appears to have been in 1999 - not their second victory over Wales, but defeat, in a little-remembered World Cup classic played at Stradey Park, Llanelli, by Argentina, who had been beaten in 1991 and 1995 and trailed by 14 points at Stradey.
You can blame New Zealand depredations, and in particular the betrayal of the islanders as a whole when Super Rugby was launched in 1995, or point to the ruthlessness of numbers as it affects a nation which, even if you include every Samoan living in New Zealand, is still much smaller than Fiji.
And no sensible opponent ever takes Samoa lightly, which may be part of the problem - they are unlikely ever again to catch somebody unawares.
But perhaps the saddest fact about that memorable victory at the National Stadium in 1991 is that, a quarter of a century on, it remains a high point rather than the prelude to greater things to come.