He would eventually captain that school team, and work his way through the representative grades.
He remembers being named in the Auckland NPC team in 1999 alongside one Michael Jones.
As a child, he had watched the Ice Man score his first try in the inaugural Rugby World Cup. Now, he was in the same team as his boyhood hero.
"My feet didn't touch the ground in that game," Mealamu says, chuckling away.
How many other young players have since felt the same way when they have been named in teams alongside one Keven Mealamu? I hope they all have.
It was all about Saturdays and game days then. It took some time for him to realise that with selection came a responsibility: to hold yourself in a certain way, to train a certain way, to be someone who stood for something more than just 80 minutes at the weekend. It wasn't until the Blues didn't want him that reality crashed his party: he had done nothing, yet.
His family reminded him of that, his father and siblings - especially his big brother Luke. Luke has always been Kevvy's right-hand man. He found, in their faith and in their honesty, the heart of the matter: to thine own self be true.
"I can be cuddly when I have to be," he says.
And he can be as tough as an algebra paper, too. You'd have to be tough to ride the Blues rollercoaster all these years.
Ever the optimist, he still thinks there have been more ups than downs in his Super Rugby career.
He deserved better on the occasion of his record-breaking game at North Harbour Stadium, when he surpassed that other gentleman Nathan Sharp to become the most capped player in the competition's history.
He should have had that moment at Eden Park. His team should have beaten the Lions.
"Still," he said about that night, "how many people get the chance to play for the team they love with, and against, these great men?"
Amazingly, the Blues taught him the value of consistency, and that's what he has always brought to his leadership. He always thought that if the leaders in the All Blacks could create an environment that no one wanted to leave, then it would be a very special environment.
"When people take ownership of that, they treat it better," he says. "I want every young guy who makes it into this team to think, 'This is everything I thought it would be, but better.'"
In the week leading up to his last Eden Park test, he was asked to find a couple of new boys to give the Bledisloe Cup a polish. He said he would do that, and that he would do it with them.
"If I had asked them to do it, that would be a job," he says. "If I did it with them, then that would be an experience."
He says he's "been lucky enough to be trusted to help set the standards in the team". Read that line back and note just how far one man can remove himself from any risk of taking any credit.
He announced his retirement yesterday - he's finally going to hang up the boots after one last Rugby World Cup. But he won't walk away from the game.
He won't walk away from the community he adores. He won't walk away from his greatest memory: having his photo taken, with his family, after receiving his 100-test cap.
He won't walk away from the one thing his dad said to him when he first played against those big city kids: "Son, when you are out on the field, you just have to play with a big heart."
