“We've been on an incredible journey,” he said. “We've loved every single minute of it. We've created memories and friendships which will last the rest of our lives.” If there was an element of talent show wannabe or Oscar winner excess in the words, anybody who was in the room listening recognised the graciousness and humility.
McCullum had spent the preceding six weeks going around New Zealand saying something similar in every port. It was, he said and kept repeating, the best time of their lives and he and his team were there to make sure they did not waste it. The effect on his team, on their country, on the game at large was remarkable.
By then, McCullum had already performed some prodigious deeds as one of the most swashbuckling batsmen of the age. He had done it in all forms of the game: a Test triple-centurion as well as a devastating and fearless limited-overs striker who steals matches. For most of the early part of his career he was also a wicketkeeper, a position he has occupied 307 times for his country in his total of 431 internationals.
It was McCullum who played one of the most significant of all innings outside the international arena. In the inaugural match of the Indian Premier League in 2008 - then in essence a gamble, its appeal uncertain - he unleashed a whirlwind. His innings of 158 from 73 balls for Kolkata Knight Riders in Bangalore was an unprecedented combination of sporting prowess and marketing man's dream.
Wearing a golden helmet which made him look like an invading god, he gave the IPL a perfect launch. It has barely looked back and neither has the game. That night things changed forever and it was McCullum who changed them. He will continue to adorn the IPL, this year fetching $1.1m (£770,000) to perform for Gujarat Lions, but he could not be persuaded to extend his international career to the World Twenty20.
As a batsman he has conjured, out of his talent and fearlessness and largely eschewing the modern accoutrements of ramps, switches and reverses, a succession of buccaneering innings. None was more brutally efficient than the 77 he blazed from 25 balls against England in the 2015 World Cup. He would deny it because he is a nice guy but he was a man on a mission that night, determined not only to enjoy the journey but to ensure that it reached a fitting terminal.
The speed of his hands and feet and his willingness to fail has marked him out as a player. But he will be remembered for more than his 21st century batting, which is why his final match as an international cricketer, in his 101st Test - all of them in succession - against Australia in Christchurch today, is such an affecting occasion.
McCullum has shown himself to be a 21st century captain, a man who encouraged his players to play as he did because he recognised that it would make New Zealand a better team. They did not simply attack with the bat, McCullum constantly supported his bowlers by setting attacking fields. He was in the business of taking wickets in whatever format he played. It turned New Zealand into a proper force and those who cited foolhardiness were ignored.
The effect of the World Cup in the country was astonishing. The nation warmed to McCullum and the Black Caps, and to cricket, as never before. If it had always been the national summer sport it had, equally, never been part of the fabric of the place. That had always been reserved for rugby union. For a few weeks McCullum changed that.
It is difficult to think of a captain in any sport who walked the walk as much as he talked the talk. When McCullum said that his team's most effective policy was to attack, he meant it and he kept on meaning it. He is, by nature, a gambling man and he loves nothing more than to watch and talk about horse racing.
If his team were consumed by the occasion when they went out for the World Cup final at Melbourne Cricket Ground in front of 93,000 spectators, almost all of whom were barracking for the home side, they had still done something that no New Zealand team had done before. And the best part of it was that McCullum had no regrets.
“No, no, you don't change your style of play,” he said. “For us to develop into the side we want to be in international cricket, we have to play like that.”
When he came to England in the summer after the World Cup, he demonstrated again that he meant it and perhaps it was not the least of his notable achievements that he took England along with him. England saw what playing like New Zealand could do and decided that it was for them as well. It made for a riveting summer in which McCullum's part should never be underestimated.
It seems an age now since he assumed the captaincy in contentious circumstances after the easing out of the previous incumbent, Ross Taylor. For months the country's cricket followers were in uproar, which made the later unalloyed plaudits the more remarkable. But McCullum rose above it all. He is, at the root of it, a thoroughly decent man who loves his job and has time for his fellow man. The team were quickly won over and gradually the country followed. They became competitive in all forms.
McCullum has come to understand his wider responsibilities to the game. He gave heartfelt evidence last year in the trial for perjury of Chris Cairns, his former friend and team-mate. Cairns was acquitted but McCullum's dilemma was apparent in the earnest way he gave his evidence, torn between loyalty to a man whom he had admired and what he saw as his duty to the game.
At 34, he certainly had more time left. But he is also a family man with three young children and international cricket is not a trade sympathetic to family men.
McCullum has been a trailblazer in another sphere too. His pride in representing New Zealand is shown by the tattoos emblazoned on his arms and body, the Roman numerals representing his cap and shirt numbers, adjacent to his childrens' birth dates.
There have been, so far, 6,283 Test runs at 38, with a record of 100 sixes, currently held jointly with Adam Gilchrist; 6,083 ODI runs at 30, with 200 sixes; 2,140 T20 runs at 35.66, with 91 sixes; and a total across all formats of 451 wicketkeeping victims. These are impressive figures which do not mark him out as a great player. McCullum the man did that.
McCullum’s career stats:
Test debut v South Africa, Hamilton, March 2004
Tests 100 Runs 6,283 Ave 38.07
100s 11 HS 302 Catches 194
ODI debut v Australia, Sydney, January 2002
ODIs 260 Runs 6,083 Ave 30.41
100s 5 HS 166 Catches 262
T20 debut v Australia, Auckland, February 2005
T20s 71 Runs 2,140 Ave 35.66
100s 2 HS 123 Catches 36
Only New Zealander to hit 300 in Tests - 302 v India 2014
First from NZ to hit 1,000 Test runs in a calendar year - 2014 (ending with 1,164)
Most successive Tests from debut (101st Test today)
Fastest World Cup 50 (18 balls)
Most Int'nal T20 runs - 2,140
Original source: McCullum - the tattooed trailblazer