A couple of weeks after Jonathan Trott's Test debut, he remarked that the experience of playing in the game, even before his match-defining century, had been "the most fun" he had ever had.

But somewhere in the intervening years the fun has disappeared. Instead of fun, there is fear. Instead of joy there is anxiety. It was telling that Alastair Cook spoke of the Ashes as being like "a war". No one enjoys wars.

Trott might seem, at first glance anyway, an unlikely candidate for a stress-related illness. He took to international cricket with apparent ease. Having scored that century at The Oval against an attack similar to that which he came up against in Brisbane over the last few days, Mitchell Johnson and all, he moved to the upper echelons of the world rankings in both ODI and Test cricket and made a habit of producing nerveless innings when they were most required. It all looked as if it came so easily.

But stress does not discriminate. Perhaps you can care too much. Perhaps, if you try too hard, you are more likely to fail. Perhaps a period of success can build not just confidence, but expectation and pressure.

Cricket means a great deal to Trott. With a cricket coach for a father and a cricket player (Kenny Jackson) as a big brother, he was steeped in the game from the start. It seemed natural when he breezed through the age group teams in South Africa and moved to England to pursue his career full time.

He flourished. With nothing to lose, he made a habit of producing match-turning contributions and seemed to have the perfect temperament. As he explained, when he was batting well, he hardly thought at all. He just played each ball on its merits and had the hunger to do so all day. He made a century on debut in 2003 and soon became a fixture in a strong Warwickshire side.

But then came the first of the serious setbacks. In the summer of 2007 he lost form so completely that he barely managed 20 and, at times, looked unrecognisable from the Jacques Kallis-like batsman who had previously dominated. It is not easy for a perfectionist to accept failure.

He reacted the only way he knew how. He worked harder; he pushed himself more. He could be seen in the nets as early as 7am on the day of games.

Jonathan Trott career timeline August 2009 - A glorious international debut with a match-winning century at The Oval as England regain the Ashes

May 2010 - Trott's appetite for occupying the crease evident in eight-hour 226 against Bangladesh at Lord's

December 2010 - Following his Brisbane epic, Trott makes an unbeaten 168 in Melbourne that helps England's to a crushing innings win and retaining the Ashes

March 2012 - England are in the midst of a crisis batting against spin but Trott shows the way with 112 in Galle

December 2012 - Scores a second-innings 143 in Nagpur that secures England a draw and an historic series victory in India

August 2013 - 16 runs in two innings in the 3rd Ashes Test at Old Trafford confirms a lean run of form

November 2013 - Bounced out twice by Mitchell Johnson in the first Ashes Test at the Gabba for just 10 and 9

And the more he pushed, the more he failed. Even on nights away from the game, he could be seen practising his trigger movements and back lift in the glass of restaurant windows, in bathroom mirrors on holiday, in clothes shops and coffee bars. He talked of the absurdity of a game in which, when in the best of form, you can play and edge a ball to slip but in the worst of form you can miss and survive. He talked of "worms in his head" that were eating away at his confidence and forcing him to overthink something that had once been so natural. He talked about giving up the game and pursuing a different career.

But he found a way through all that. Partly through the support of Ashley Giles and partly through the support of his wife, he found the stability to deal with the inevitable setbacks that occur in a career as a batsman. He learned to accept that, as long as he had prepared well, he had to accept the occasional failure.

To prevent those intrusive thoughts entering his head, he settled upon a formula. He would make that famous trench in the pitch between deliveries; he would fiddle with his pads; bend his knees; check his boots and gloves. Anything it took to ensure there was no time to let those thoughts creep back.

He was mocked by some. They found him compulsive and robotic, missing the point that it was a tactic to deal with an excess of emotion. It was a tactic to avoid the dark thoughts that have always circulated but have only now settled upon him.

It worked, too. He produced some magnificent innings for England. Innings that shaped matches and series; innings that earned him respect from opponents around the world. Great innings.

"You should talk to me after I've failed," he said, one day after making a century. "There's no point talking to me after I've got runs. You won't learn anything that way. I don't think anything when I'm scoring runs. It's when I'm not scoring them that you could learn something."

There were some setbacks along the way. They were always away from home; nearly always towards the end of a long tour. Without his normal routine and without the comforting influence of family and home, there was no one to tell him it was one bad innings or one bad game; no one to limit the scale of the failure or remind him of the perspective. No one to tell him to turn off the TV and get some sleep. The England management knew this and managed it well. While there are times the England camp can be somewhat cliquey, there is no more anyone could have done - players and support staff - to be supportive and sympathetic in the last few days.

Why has the situation now peaked? The struggle against Mitchell Johnson in Brisbane may have been a catalyst but it is not the cause. It may have unmasked the problem, but it is not the underlying issue. It is more likely that this has been an accumulative issue which has been building and subsiding for many months. Maybe this Ashes series, coming so soon after a high-pressure tour to India, a Champions Trophy campaign that meant more to this England team than many realise and then back-to-back Ashes series have taken their toll.