But as he paraphrased the quote first attributed to the great English poet William Blake, Clarke muddled his point ever so slightly when he added that ‘nobody has got it’.
The reality, of course, is that everyone has hindsight and there is no shortage of Scotland supporters employing it vigorously as they continue to dissect Clarke’s team selection for the 2-0 defeat against Czech Republic which has seriously diminished hopes of reaching the knockout phase of the Euro 2020 finals.
But rather than being wise after the event, what the Scotland manager needs now is to channel the original second part of that famous Blake line which states that ‘foresight is better, especially when it comes to saving life, or some pain’.
As Clarke looks to avoid the pain of a defeat against England at Wembley on Friday night, which would leave Scotland’s prospects of qualifying from Group D hanging by a thread, he must be contemplating significant changes to his starting eleven.
In every department of the side which came up short in an anticlimactic occasion against the Czechs, there is a case for fresh faces being introduced.
David Marshall’s name prompted an especially loud cheer from the Scotland fans inside Hampden on Monday when the teams were announced over the PA system. It was recognition of the heroic status the Derby County man rightly enjoys among the Tartan Army for his memorable contribution to Scotland qualifying for their first major tournament finals in 23 years.
But sentimentality shouldn’t be a factor in who is the country’s number one goalkeeper. Any cold-eyed assessment of the options available to Clarke in that position should conclude that Craig Gordon is the most accomplished of them.
Marshall’s error in getting his geography so badly wrong when undone by Patrik Schick’s stunning long-range goal for the Czechs may have come as a consequence of instructions to push up when playing behind a back three and is not a stand-alone reason why he should miss out at Wembley.
But even at 38, Gordon has an ‘X’ factor as a goalkeeper – similar to his fellow veteran Allan McGregor who is sadly no longer available for Scotland – which sees him pull off unexpected and exceptional saves at crucial moments in big games. That’s why there is a compelling argument for him to play on Friday.
It was unquestionably a savage blow for Clarke to lose the services of Kieran Tierney in the build-up to Monday’s Group D opener.
The tactical awareness, athleticism and dynamic ability to break forward and supplement the team’s attacking prowess had picked out the Arsenal defender as a potential star of the Euro 2020 finals.
Let’s hope Tierney can recover from his unspecified ‘niggle’ in time to return to the back three against England.
Getting caught in possession or straying out of position is likely to be severely punished by a pacy English attack. To that end, even if Tierney doesn’t make it, a change at the back may be on Clarke’s mind – perhaps with Scott McTominay dropping into the back three alongside the robust duo of Grant Hanley and Liam Cooper.
Let’s start on the left – no debate necessary. Andy Robertson was Scotland’s best performer against the Czechs by a distance, albeit he would feel he should have converted his first half chance which was brilliantly saved by Tomas Vaclik.
On the right, it’s a very different matter. Stephen O’Donnell has served Clarke admirably but the Motherwell man had a torrid afternoon on Monday.
It’s no disrespect to O’Donnell to state that both of Scotland’s other options for the role, Rangers’ teenage right-back Nathan Patterson and Celtic winger James Forrest, are far more talented players.
Forrest looked lively when he appeared as a substitute in the second half against the Czechs and his experience probably merits him being given the nod against England. But Patterson has appeared completely unfazed by any challenge set for him in his fledgling career and could also thrive on the Wembley stage.
Clarke made one of his most surprising calls on Monday by omitting Callum McGregor from his starting line-up. The Celtic man has an ability to dictate the tempo of proceedings in midfield, something the trio of McTominay, John McGinn and Stuart Armstrong were simply unable to achieve against the Czechs.
Armstrong looked especially off the pace and it would be no surprise if he misses out against England.
While the return of McGregor is the most likely call for Clarke to make, he must surely also be giving serious consideration to a role for Billy Gilmour. The Chelsea prodigy has shown he can compete with England’s best at club level and could bring Scotland greater composure and a sense of security in midfield.
If Clarke could get Monday afternoon back, he would surely start Che Adams up front. The Southampton striker gave Scotland far greater balance when he replaced Ryan Christie at half-time and must surely lead the line against England.
Lyndon Dykes struggled to impose himself physically against the Czechs and also missed a couple of decent chances, adding to the feeling he lacks the predatory instincts required at the highest level.
Adams has already done enough to suggest he can be trusted to be the spearhead in attack for Scotland, perhaps with McGinn in a more advanced role playing just off him.
Plenty to ponder, then, for Clarke who, as ever, won’t be short of free advice on the matter. But, for what it’s worth, here’s my team for Wembley in 3-5-1-1 formation: Gordon, Hanley, Cooper, Tierney; Forrest, McGregor, Gilmour, McTominay, Robertson; McGinn; Adams.