There's been a strange and unfamiliar intruder in England's dressing-room over the past few weeks. A haggard old demon of doubt, sitting on the shoulders of some of the most unfettered cricketers of their generation, and cramping their style with whispers of impending doom.
Perhaps it's not a fear of failure per se that's been holding England back in their anodyne displays against New Zealand and Afghanistan, but a recognition of finality - an unconscious acceptance among this remarkable group of players that the end is nigh, no matter how well or badly they play.
After November 19, come what may, many of these players will never play another ODI, let alone feature in another 50-over World Cup. Some, like Liam Plunkett after the 2019 triumph, may never play for England in any format again.
As such, it would be understandable if a few real-world concerns have overwritten the team's keenest exhortations to "play our way" and "attack" the World Cup, as per Jos Buttler's oddly manic pre-tournament pronouncement.
And as the squad gathers in Mumbai ahead of Saturday's immense clash with those inveterate World Cup worriers South Africa, the shrinks have been out in force, seeking to defankle the knots in England's psyche.
There's Ben Stokes, the team's "spiritual leader" in the words of head coach Matthew Mott, calling for England to "go down doing what we're known for". And then there's Brendon McCullum, whose role as an ambassador of the New Zealand meat-exporting industry just happens to have given him an excuse to stay in the team hotel in Mumbai this week.
England "need to stay true to their method which has brought them so much success," McCullum told the Times this week, and seeing as it was his influence, way back at the start of their journey in 2015, that instilled the method in the first place (long before he transferred it onto the Test team), no one's better placed to preach that particular message.
Without wishing to get reductive about the mindset that has given England their superpowers across formats in recent years, the broad thrust of "Bazball" (as no one in McCullum's presence will dare to call it) has been about embracing the joys of playing sport for a living - of casting aside the doubts and cynicism that come with age and wisdom, and just remembering how much fun it used to be to play the game as carefree kids, without a jot of expectation about the endgame.
How much fun it was, to use a random example, when Joe Root sidled up to Buttler in the middle of the Wankhede on March 18, 2016 and - with 82 runs still needed from 48 balls - declared to his team-mate: "We're cruising this - we're absolutely cruising this."
For it was at this venue seven-and-a-half years ago, at a similarly make-or-break juncture of their first major tournament of the post-2015 era, and against the same opponents too, that England's white-ball thrusters took their first steps towards immortality.
"Embrace the naivety" was Eoin Morgan's rallying cry in his team's unlikely run to the final of the 2016 World T20, a seemingly throwaway slogan at the team's arrival press conference in Mumbai, but one that took on a life of its own as his greenhorn charges defied expectations time and again (at least until their fateful ending in Kolkata, when the limits of winging it finally caught up with them).
Going into that tournament, Morgan had been the only member of England's squad with prior IPL experience. Under the directorship of Andrew Strauss, the ECB were on the brink of a new, more laissez-faire attitude to overseas franchise leagues, and in February that year, Buttler had become a notable signee for Mumbai Indians.
But until that moment that Carlos Brathwaite launched Stokes' final over of the tournament into the history books, England had cast aside any doubts about their readiness for the challenge, and simply set about enjoying the ride of their young lives. And never more so than in their group-stage clash with South Africa, where they hunted down a massive target of 230 - still to this day the highest chase in T20 World Cup history.
Then as now, England's backs had been against the wall after a shellacking in their previous group game - albeit there is a world of difference between being bested by arguably the greatest exponent of T20 batting, Chris Gayle, in an 11-sixes onslaught, and being hounded out of Delhi by Afghanistan.
Nevertheless, as many as ten survivors from the South Africa contest might find themselves locking horns once again this weekend - a remarkable seven from England's ranks alone, with Root, Buttler and Stokes returning alongside Moeen Ali, Adil Rashid, David Willey and even a young Reece Topley, whose second and final appearance of that campaign comprised two overs for 33 runs, and would be his last in England colours for four injury-plagued years.
For Root, however, the South Africa match was his single finest hour as a T20 batter. He would play six matches in that campaign, and had the final gone England's way, he would have been a shoo-in for Player of the Match and Tournament. And yet, for reasons of raw power on the one hand, but moreover the time constraints of his Test captaincy and ODI pre-eminence on the other, he's only ever featured in 12 subsequent T20Is, and none since 2019.
But on that night of nights, Root's 83 from 44 balls was a declaration of his genius - a performance of incredible stillness, not unlike Aiden Markram's recent 49-ball century against Sri Lanka in fact, in which the virtues of placement and poise transcended the blood and fury of headlong attack. In fact, until the moment of his dismissal, with 11 runs still needed from 10 balls, Root faced a mere two dot-balls out of 43 - and the first of those he would swear blind was a wide.
In the course of his innings, Root even unfurled a prototype Root-scoop - a startlingly effective inverted ramp over third man for six, to bring up a 29-ball fifty. "How do players think of shots like those? Let alone execute them. What a world..." wrote Will Luke on ESPNcricinfo's ball-by-ball commentary. Root for his part later admitted in White Hot, the recent book about the team's rise and rise, "my heart felt like it was pounding out of my chest … thankfully it was exactly where I wanted it".
This contest was not the first stirring of England's bold new approach - that had come the previous summer against New Zealand and Australia, a thrilling pair of seat-of-the-pants rides that would finish 5-5 across the ten ODIs but later be recalled by Morgan as his favourite games in their run to the 2019 title. And to all intents and purposes, the World T20 had arrived too soon to draw any long-term conclusions about England's new-found aptitude. Even so, an early elimination from yet another global tournament would have done the rebooted project no favours whatsoever. Whether they embraced the implications or not, the Wankhede chase was a de facto stress test of their no-consequences attitude.
In the final analysis, they passed it with flying colours, with Jason Roy's thrilling powerplay onslaught providing the bugle blast. He cracked 43 from 16 balls, including five fours, three sixes and - in league with Alex Hales - 44 runs from the first two overs of the chase.
Kagiso Rabada bore the brunt of the first of those - he disappeared for 21 runs, including one of the most rifled straight drives that has ever been executed on the world stage - and he'll be one of three South Africans back for the rematch on Saturday. Neither Quinton de Kock (52 from 24 balls) nor David Miller (28 not out from 12) has any personal reason to regret their efforts on the night, and the presence of each of them will be a reminder of quite how much situational knowhow will be distilled into the coming contest.
"It was a fantastic game, one of my favourite games," Buttler said in Mumbai on the eve of the rematch. "It had a lot of value in terms of where we were going as a team. It's a long time ago, and that style is a different format, but we want to find different ways to put the opposition under pressure. It doesn't always mean fours and sixes, it means can we push back when the opposition is on top, or take the initiative in different ways? That's what we want to live by as a team, and when we commit to that, that gives us the best chance of positive results."
The challenge for both teams, therefore, will be to play without fear - like the kids that they used to be - yet manage the clutch moments with the wisdom that comes from such vast tournament experience. In terms of accessing such an elusive mindset, therefore, "embracing the naivety" is clearly no longer an option for England's weary worldbeaters, although the manner of their eventual defeat in that year's final might yet offer them some solace in their current plight.
With two global titles in 2012 and 2016, and a further run to the final in between whiles, West Indies' T20 team of the mid-2010s is perhaps the only recent international dynasty to rival the side that England have compiled over the past eight years. And the cool-headed mugging that they instigated in the heat of the moment in Kolkata serves as timeless evidence that - contrary to the impression that England's frazzled veterans are currently giving off - experience when the going gets tough actually counts for everything.