A month was all it took. Alastair Cook has changed, Planet Cricket has changed. He has passed from stoic opening batsman to substantial leader, from Mr Dependable to Captain Fantastic.
England are 2-1 up in the Test series against India, having recovered from an abject defeat in the first match at Ahmedabad where familiar shortcomings were paraded like dirty laundry. Cook launched the revival there in the second innings, his first match as official captain, and has led since by inspiring example.
The statistical milestones have come and gone: the youngest player to score 7,000 Test runs; the first England batsman to 23 Test hundreds, surpassing the number of 22 first achieved 73 years ago; an unprecedented five hundreds in all his five matches as captain; the longest time spent at the crease across three Tests in India.
All this he appears to have done without breaking sweat in any sense. Cook is a legendary non-perspirer, which is why he had the job of the team's ball-shiner-in-chief until he became captain. That important task has now been passed to other hands because Cook has his full with other duties.
These monumental batting feats have doubtless helped to hasten another development. This England have palpably become Cook's team now, not simply one he inherited. For that some passing credit should be accorded Andrew Strauss, his eminent predecessor. Strauss knew when it was time to go.
Cook would certainly recoil at his elevated status. But it is natural for there to be heroes in sport and here is a player who has scored 548 runs in six innings at an average of 109, while his team stands on the very cusp of winning a Test series in India for the first time in 28 years.
India have not lost a series at home for eight years and that was but one in the last 23. These are all achievements of an extremely high order but Cook knows that Nagpur, venue for the fourth Test which begins on Thursday, could dilute everything that has happened so far if a dispirited home side somehow respond. On the whimsically viperous surface which is bound to be prepared it may take more than resolve to prevail.
Cook will be the same as ever, concentrated, tenacious, single-minded, controlled. The description that is most often used about him is that he is tough but it is not a toughness as in tough guy, manifesting itself in outward aggression; it comes from an inner core and a recognition of limitations which is at the heart of many who succeed on the grand stages.
He first pitched up at Essex as a kid not long out of St Paul's Cathedral choir school, where many of those rudiments of discipline and self-reliance were inculcated. Maybe the England and Wales Cricket Board should scour the ranks of 10-year-old choristers for future batsmen the way they used to shout down pits for fast bowlers.
From almost that moment, Graham Gooch, Essex man, one of England's greatest batsmen and now the team's batting coach, has known Cook. He cannot quite remember when they first met but he recalls one fundamental aspect.
"Alastair was on the academy and it was pretty obvious he was going to be a good player," Gooch said after England's seven-wicket win at Eden Gardens. "I can't remember the first time I saw him but I do remember him keeping wicket and batting for our Board XI against Essex in a proper match.
"My early memories of him as a person were that he was very mature for his age and very balanced and considered. He went about his cricket in a methodical sort of way and you can still see that now. The priceless ability he had when he was young, and again you can see this now, is that he knows exactly what he can do and what he can't do. He puts that in place and into practice and doesn't step outside that."
For now, Gooch remains as England's leading Test runs scorer with 8,900 (he made 20 hundreds). Of the present batting order, Kevin Pietersen (7,325) and Cook (7,103) are in hot pursuit. Ultimately, Cook who will not be 28 until Christmas Day, should easily surpass his mentor.
"I hope to hang on in this job until he goes past my record," said Gooch. "In my opinion, 27 to 35 are the best years for a batsman because you have honed your knowledge and know your game. I think he's got his best years in front of him.
"He's got to stay fit and motivated but nothing at the moment would suggest to me that that won't happen. It's difficult to predict but let's just say the opportunity is there for him to do all those things you'd like to write about.
"He's not the most eye-catching player, I've said that many times, but he gets the job done. You know the old saying? It's not how, it's how many. He knows the way to play. Often young players coming up have talent and ability to strike the ball but they don't quite know how to manage their ability. Sometimes it dawns on them later in life and sometimes it doesn't dawn on them at all, but this lad had it from the beginning. He knew how he could operate."
It is one job being a phlegmatic batsman, a churner-out of runs, it is two being that and the team's captain as well. Of Cook it could not perhaps be said he is an instantly natural leader but his dogged determination to do it well – that inner core again – means that he will not fail easily.
These two significant victories apart, he has already also achieved the considerable feat of ensuring that Pietersen's return to the team was seamless.
The change is apparent to those who have observed him in this England team since the start, almost seven years ago. He knew how to bat then and learnt more quickly but there are peripheral necessities to being an international sportsman in the 21st century.
Grossly unfair though it patently is, they are expected to put their deeds into words. Reporters, an unreasonably demanding legion of men, expect Cook and his like to be articulate not only with a cricket bat.
There are several examples to chart his progress. In Nagpur, whither he returned yesterday, he made his Test debut in March 2006 and was bewildered by the attention after his maiden century, just about explaining his long journey across the world from Antigua, where he had been playing for England A before an emergency call-up.
In Brisbane on the last Ashes tour he was paraded before the press as vice-captain before the first Test and was clearly nervous. With the gross unkindness that only reporters can muster, someone counted the number of times he said the word "obviously" as a verbal tic (it was 37).
Maybe marriage to Alice has helped, maybe finding a role outside cricket has done its bit. His wife's family are farmers, Cook has taken to it readily and willingly. Down on the farm he thinks not of nor longs for cricket, and that is as it should be.
Late on Sunday morning, Cook came in after the victory and was illuminating and confident. He said obviously once, from memory, but he obviously had to do so. This is a young chap maturing naturally but it is also Cook learning what is expected of him in this job.
"Captaincy has enhanced his run-scoring already," said Gooch. "It's difficult to look into a crystal ball and say whether it will affect him down the line but all the opportunities are there for him.
"He's mentally strong, that's his greatest asset, and he could achieve a lot of the things you're talking about. There's a lot of cricket in front of him and that can affect you but I'd like to think he will go all the way.
"I think we've seen already in the dressing room that he's prepared to make his own decisions. He doesn't always take the coaches' advice, in that he wants to do it his own way. He'll make mistakes and he won't get it right every time. You have to grow into that job, the way you get the best out of people, counsel them, and make tactical decisions. All those things come into it. He's in his infancy but I don't see any reason why he won't be a good captain and leader of men," Gooch added.
Of his five matches as captain thus far, England have won four. His batting average as captain is 111.25 (Gooch's was 58.72). Mere figures actually, but figures that embellish the man. Being the captain of England can only get tougher from here. Cook certainly knows that, but he will not be looking beyond Nagpur on Thursday. A month is a long time in cricket.
1996 Plays for Maldon CC Third XI adult side - aged 11. 2003 Hits 1,181 runs in season for Bedford at average of 168. Hits 69 on Essex debut, batting with his future England coach Andy Flower. 2004 Captains England U19 at World Cup. Scores maiden Essex ton. 2005 Hits double ton for Essex against Australia. 2006 Scores century on England debut against India. 2007 Becomes second batsman to hit 1,000 Test runs in maiden year. 2008 Youngest Englishman to reach 2,000 runs. 2010 Youngest Englishman to reach 4,000 runs. 2011 Youngest Englishman to reach 5,000 runs. 2012 Made England Test captain. First Englishman to hit 23 Test centuries. Youngest ever to 7,000 Test runs.
1996 Plays for Maldon CC Third XI adult side - aged 11.
2003 Hits 1,181 runs in season for Bedford at average of 168.
Hits 69 on Essex debut, batting with his future England coach Andy Flower.
2004 Captains England U19 at World Cup. Scores maiden Essex ton.
2005 Hits double ton for Essex against Australia.
2006 Scores century on England debut against India.
2007 Becomes second batsman to hit 1,000 Test runs in maiden year.
2008 Youngest Englishman to reach 2,000 runs.
2010 Youngest Englishman to reach 4,000 runs.
2011 Youngest Englishman to reach 5,000 runs.
2012 Made England Test captain. First Englishman to hit 23 Test centuries. Youngest ever to 7,000 Test runs