Here's something I have never talked about. Perth, December 16, 2006. It should have been one of the high points of my life: sitting in our changing room at my home ground, the Waca, watching some of my best mates bat our way towards regaining the Ashes.

Ricky Ponting and Matthew Hayden, as close friends as any I had in the game, built upon the partnership they'd started the night before, putting on 144. Then it fell to Mike Hussey, my firm friend here in Perth, and the youngster Michael Clarke - these two were on their way to centuries in the innings-defining middle-order partnership of 151. Our team plan was all about friendship and partnerships, building totals in mini-teams of two, and this day, first Ricky and Matty, and then the two Michaels, were showing our true character.

We were up 2-0 in the series, we had a 29-run lead on the first innings, and now we were batting England out of the match. Surely we'd be able to close out the series and bury all those demons from the worst year in our lives.

The Michaels - Hussey and Clarke - batted through the middle session. Our lead edged up to 250, then 300, 350 ... all going to plan. In the changing room my team-mates were getting that taste - of revenge, of redemption - in the backs of their throats, but holding it down, trying not to get ahead of themselves.

It doesn't get much better than this, surely. So why was I sitting in that room with my gear on, ready to bat yet forcing down the tears? They weren't tears of joy - far from it. Why was I as churned up and miserable as I'd ever been? Why was I thinking that this was the end, the very last time I'd be sitting here?

At that moment, which should have been one of the best, I was resolved on quitting cricket. The day before, I'd sat in my car outside the Waca and poured my heart out to my manager, Stephen “Axe” Atkinson. I was going to retire, I told him. It had all become too much.

In the first innings I'd lasted three balls before pushing at one from Monty Panesar, misjudging the bounce and getting caught in close. Another failure, another slip down the greasy pole which I'd been steadily sliding down for 18 months - since that England tour when Andrew Flintoff exposed me with the same obvious tactic again and again.

It was almost automatic. I'd come in, Flintoff would come on, he'd bowl around the wicket, I'd get out. I started to feel that I'd been fluking it in Test cricket for a few years and now reality was catching up. I wasn't as good as my record suggested. The reputation I'd built over seven years in the Test team, I was undoing it all. I wanted to get out before I did it any more damage.

For 18 months since England, I'd been in a kind of mortal combat with my doubts, and it was showing. Those close to me saw how cranky I was, how dry and tired, how little I was enjoying it. Memories of the 2005 tour , which was such a nightmare both personally and professionally, were eating away at me slowly. In South Africa, in early 2006, when André Nel was getting me out with the exact same tactic as Flintoff, I'd got so sick of it that I'd written down four words, in an angry, passionate note to myself, that I would never have expected to say: “I hate this game.”

Hussey and Clarke kept batting. Our lead inched up towards 400. England couldn't catch us now, could they?

Here's another thing I haven't spoken about. Just a few steps from where I was sitting, in the back of that Waca changing room, a little under a month earlier, I'd been sitting with my face in my hands bawling my eyes out. I'd made a hundred in a domestic one-dayer, a 63-ball blitz, and I came into the rooms, hid in a corner and had the biggest cry. Yet again it should have been a moment of happiness, but I felt lost: thrilled that I still had that ability to score a century, uncertain if it would remain with me at Test level. What was going on with me?

Shortly before tea Huss got out, caught behind off Panesar for a tough, brilliant 103. I put my pads on, but we were OK. Andrew Symonds was going into a situation tailored for him.

For me, it was time to hand over to guys like Symo who still had their point to prove. There were strong rumours that Shane Warne, Glenn McGrath and Justin Langer were going to retire at the end of this series. Possibly Matty Hayden too. I was still reeling from the events of the previous week, when another of my very closest friends in the game, Damien Martyn, had walked off into the sunset in the most puzzling and disturbing circumstances.

I still hadn't had a proper talk with Marto, still didn't know what happened that night after the Adelaide Test, still didn't know why he'd walked out. It was hurting me. I missed him. As I'd said to Axe when I was sitting in my car: “It's time. I just know my heart isn't in it any more.”

Axe hadn't said much. He'd listened to me politely and agreed with everything I'd said. But during that second day, when we'd gone out in the field, Axe had called my wife, Mel, and let her in on my secret. She had sensed something was coming. She and I had touched on the subject of retirement but she couldn't have predicted that when I walked out the door that morning I was making the decision that very day. I'd had her at the front of my mind when I told Axe. Mel and I had two toddlers, Harry and Annie, and she was eight months pregnant with our third. Balancing the cricket life with my family was becoming too hard for me; I didn't want to feel torn in two any more.

After making my decision, I'd gone about my business with a feeling of relief. I was retiring. It would be OK.

During Perth Test matches I stayed at our home rather than with the team at the hotel. When I got home after that second day, Mel cut straight to the chase and let me know exactly what she thought of my grand plans. “You're kidding, aren't you?” She gave me all the reasons in the world to play on. She didn't think I really wanted to quit but was throwing a kind of tantrum over the duck I'd made the day before. “Get over yourself,” she said. “Stop moping about getting a duck. Why do that now? You've never done it before.” She knew me like nobody else in the world and was spot-on.

More than that, she was livid, because I'd gone and apparently made my decision without seriously consulting her. We were on this journey together, we always had been, so what gave me the right to quit unilaterally? If I was going to quit, she said, it had to come out of the two of us talking it through, and that couldn't happen in the middle of a Test match during one of the most important series in my career. I wasn't thinking straight, she said. Then, as she's done all along, she went directly to the heart of the matter. 'Why are you still beating yourself up over one failure in 2005?'

She said I wasn't giving myself credit for the good innings I'd played since then. She knew what was going on inside me. I was still wounded by 2005 and couldn't pick myself up. I'm sure there must be other heavily pregnant mothers of two who've talked their husbands out of retiring from international cricket, but I can't name any off the top of my head.

We discussed it in a more civil manner through the night. When I came to the ground for day three I was still absolutely sure I was going to retire, not after this Test but at the end of the series. I don't know how much of that resolve was pure stubbornness, me not wanting to admit to Mel that she was right. In my disordered mind one thing was crystal clear: this was the end. I was finished.

Just after tea Symonds got out for two, another wicket to Panesar. Our lead was 394. The English were jumping around, urging each other on, saying they could knock us over quickly now, they were into our tail. They might only be chasing a little more than 400, and they could get that.

It's a terrible thing for your self-confidence when your opposition sees you as a puzzle that they have already solved. I put on my gloves and helmet, picked up my bat and walked down the Waca race. For the last time? Yes. Panesar had taken the Symonds wicket with the last ball of his over, so the next ball would be bowled by - who else? - Flintoff.

I crossed the boundary rope. In a superstition I'd followed since I was a kid, because somehow it made me feel safe, I stepped on to the field with my left foot first.

I don't want to gloss over that innings, but the truth is that when you get into that mental state, the “zone” or whatever they call it, you can really have a hard time remembering it. My recollection of the next hour is that things happened almost too quickly for me. I've seen a five-minute highlights package of my innings and thought: “I don't remember that.”

At the start I was scratchy. Flintoff put himself straight on, bowling around the wicket of course. I edged one of my first balls between third slip and gully and was only a yard from being caught. The next two balls I let go, then I hit a back-foot cover drive for four. It just felt perfect. That got me up. Some things trigger you.

Freddie tried bowling a bit wider, and I cut a few away. I kept saying: “Back yourself.” Panesar came on, bowling into a strong breeze - which meant that I'd be hitting with it, and I thought: “If I'm going to go, I might as well go positively.” By the time I got to 20 or 30 I'd forgotten all my self-centred thoughts and was concentrating on what the team needed. A cricketer is always at his best when he's focused externally. I wasn't asking myself: ‘Am I up to it?' With my bat, I was putting the question to the opposition: ‘Are you up to it?'

We were getting towards the end of the day, and asked for a thumbs-up from Ricky if we were to go for fast runs and a declaration, or a thumbs-down if he wanted us to bat through to stumps. Pup [Clarke] and I thought we saw a thumbs-up, so we went for it.

Pup had just reached his century, and I was fully in the mood now. It was the same time of day, and the same place, as my hundred in the Ford Ranger Cup a month earlier. This time I got to three figures even quicker. I didn't know about Viv Richards's 56-ball world record until later, and missed breaking it by two balls. I don't mind: Viv is Viv.

It was only when we came in that Ricky said: “What was that all about? I wanted you to bat through to stumps.” We said we thought we'd seen a thumbs-up.

Next week: How the Poms taught me to drink