At the age of 39, having spent almost half his life as a professional rugby player, Dan Carter has retired. Dan Carter: My Story by Dan Carter and The Spinoff managing editor Duncan Greive, and published by Upstart Press, was published just days after his man-of-the-match-winning performance in the 2015 World Cup final. Here, the man ranked by many as the greatest No 10 of them all reflects on the match fresh from holding the trophy aloft at Twickenham.

All I had wanted was to put my hand on the trophy. To have played a role in winning it. To feel a part of the Rugby World Cup experience, while being something close to fully fit. For so much of the past year that felt impossible. Not worth thinking about. I was so far behind Crudes and Beaudy. Playing out of position for the Crusaders, my leg giving me lingering trouble.

Now, I’m sitting here, a few hours after the fulltime whistle. A Cup Winner’s medal around my neck. Man-of-the-Match in the World Cup final, my last game for the All Blacks. A scenario I’d never even have dared imagine.

One thing we talk about over and over with this current All Blacks side is about never focusing on the outcome. We view the outcome as a function of following our processes. That might sound a little dry to some, but looking back at every major loss we’ve had over the years, they mostly started with us thinking too far ahead of the game. That’s a big part of the emotion I’m feeling right now: the absence of a battle I’ve been waging all week. In fact, to a certain extent, it’s one I’ve been waging since 2011: never think of the stakes; never think of the outcome.

For four years this moment has been a long way off, and often deeply improbable. I’d sit down with Gilbert Enoka, our mental skills coach, and he’d help me get away from my thoughts, designing a programme to cover a few weeks, or a day. Even hours at times. This week was a different kind of psychological challenge. What was looming wasn’t a rehab, or a selection, or a test. It was what I’d wanted my entire life. I’ve dreamed of this moment ever since I saw David Kirk’s All Blacks light up the country in 1987.

Think too hard about the magnitude of that desire — and how it would be boiled down into 80 minutes — and you’ll be overwhelmed. So for the past week I’ve been constantly avoiding thinking about the Saturday at Twickenham. Instead, it was always about whatever was directly in front of me.

This morning I woke up and logged out of my social media accounts. I wanted to shut out all the expectations. Of fans, friends and family. Even the fact my All Blacks career was ending. To think only about the game, and how we, as a team, would like to play it.

The opening whistle was a relief, when it finally blew. Before then it was about controlling and directing my thoughts; now they would respond instinctively to what came at me on the field. Some games take a while to reveal their character. You don’t immediately know what you’re in for. Not this one. You knew that it was a final, and everyone on the field had ratcheted up their physical commitment to its maximum potential. That was obvious from the start. I didn’t have to make many tackles early, but was in awe of what my teammates were doing to the Wallabies.

The collisions were ferocious. Jerome made a big tackle. Then Conrad. Then Brodie. All of them were just so dominant. It set the tone for the whole match, a degree of effort unlike anything I’ve ever experienced before. It was everything I wanted the game to be. Early on I got hit late. Nothing too serious, but enough to wind me, and make me determined to make them pay from the kick. Not long after, I copped a high shot. This time within range of the posts. Each time I got up determined to nail the corresponding penalty. I want to make every kick — but I knew with each of those that the best way to remove the target from my back was to get up and make sure I made them pay.

The game began to open up. Nehe scored in the corner, finishing off some brilliant work, the perfect way to head into the half. During the break we were deeply focused on starting well. Thanks to Ma’a’s amazing run, we did. That try put us up 21–3. Exactly where we wanted to be. But it also meant we began to take our foot off the throttle. You could sense the team relaxing a little, yet we felt powerless to stop it. A little was all Australia needed. After Ben got carded the Aussies surged back. They were immense through that period, and tactically brilliant. The two tries came so quickly, and that lead we’d ground out vanished in minutes.

We regrouped as 15 men after Ben returned, needing to reassert our authority over the game. It wouldn’t be easy. I was absolutely buggered at that point. I like to think I’m one of the fittest guys on the team, but my legs were just so heavy. We couldn’t let them know that, or allow fatigue to dictate our decision-making.

From the restart, logic might have suggested we kick the ball long and play for territory. That’s what we’d done with Ben off. But it hadn’t worked, and we decided to attack with the kick and go short. I didn’t get it quite right, but somehow the very act of making an aggressive rather than defensive decision helped us snap back into the right mindset. We tried to set up for a dropped goal, but couldn’t get the position right. Still, I felt confident.

Then, two minutes later, Aaron hit me with a pass unexpectedly. Not having thought about what I’d do with the ball freed me up to play more instinctively. I made a snap decision to go for the dropped goal. I wanted that seven-point margin back. It sailed over.

A few minutes later we were awarded a penalty just their side of halfway. Richie and I debated whether to go for the corner. I decided to have a shot. It was at the very limit of my range; but I felt that, with the adrenalin of the day, I should have just enough to get it across. Again, it worked.

That gave us 10 points, and breathing space. Not enough to relax — we’d learned how dangerous that was already — but to play with an edge, a confidence. Then, as the minutes wore down, Beauden scored a try to take it beyond doubt. I lined up the final conversion, knowing that the game was beyond their reach. I was struggling to contain my emotion when Liam Messam came out with a tee. He asked: “Are you going to kick it with your right?”

He was reminding me of a conversation I’d had with Aaron Smith an eternity ago, way back at the start of the Cup. I’m a leftie, but for years I’ve practised kicking with my right foot. Not for any serious reason; I guess it just goes back to the kind of backyard ball tricks you do as a kid. I had said to Aaron that I’d love to kick one right-footed before I retired. Even saying it aloud felt like a premonition.

And here I was: my final kick in test rugby, the game beyond doubt. I never wanted to do anything to disrespect that incredible Wallabies side. But the idea felt irresistible: like a line running straight back through this World Cup, through the personal pain of 2011, and the team’s pain of 2007. Through the Bledisloes, and the Lions series. Through my whole career.

Back to where it all began for me. On a muddy section, alongside my parents’ house in Southbridge, where rugby was just the most fun a kid could have. At the end of my international career, a line back to the very start. I had no choice. I lined it up. Walked in, planted and swung through with my right. And, just like that, it was over.

Dan Carter: My Story is published by Upstart Press