Someone should tell Andy Murray those things that seemed to escape him utterly yesterday in his third and, in all the circumstances, feeblest attempt to win a Grand Slam final.
Most vitally, you do not back into one of the defining moments of a potentially great career.
You don't go on repeating the same old mistakes. You don't get lost in rambling, foul-mouthed monologues, or body language that could intensify the gloom at a funeral.
You exploit the game you have been given and the one upon which you have worked slavishly hard.
You don't allow someone as accomplished as Novak Djokovic, who has already beaten you by three years to his first major title and just a few days ago stripped down Roger Federer, to set the terms and move smoothly along at his own pace.
You don't have to charge the net, kamikaze style, and try to make every shot a drop-dead winner. But you do have to believe in yourself a bit – and you do have to step out fearlessly on to at least a little new terrain.
While Murray and his entourage appear ever more introspective, Djokovic, give or take the odd moment of fleeting doubt – invariably created by a flash of talent from Murray that reminded us of why his lame-duck performance was quite so exasperating – looked every inch what he has become. This is to say an authentic major tennis player who can reasonably challenge the great Rafa Nadal in the coming years.
Djokovic, for all his ability, hasn't always looked a sure-fire champion in the making. Federer has questioned his resolve on several occasions – and suggested his idiosyncratic, ball- bouncing service preparation is symptomatic of a lack of confidence in his own technique. Yet in the company of Murray yesterday he looked like someone who had set himself apart.
At times, frankly, it was a pretty much finished sportsman against someone who more than anything resembled, well, a rather screwed-up adolescent.
These may sound like harsh reactions coming so soon after the admiration Murray earned in his excellent management of the semi-final against the resolute Spaniard David Ferrer. Then, Murray was put under severe pressure but instead of breaking him, as yesterday, it provoked a performance of great competitive maturity and some tactical brilliance.
That Andy Murray went so completely missing yesterday that one instinct was to send out a search party to trawl the local beaches.
One conclusion was bleakly inevitable. It was that while Djokovic has grown up, most visibly, his admirers say, in his leadership of Serbia to a Davis Cup triumph, Murray resembles nothing so much as a case of arrested development. Arrested, this is, at the point where his fine talent and demonstrable dedication should be inflicted consistently on those big moments which shape a career.
A year ago, Murray wept after being swept away by Federer for the second time in a Grand Slam final. Yesterday, he commented that this time his emotions were under better control – but the cruel fact was that it didn't matter anymore; the time for him to be the master of himself had again come and gone.
Djokovic's Davis Cup triumph is said to be a huge source of his new comfort in his own skin and there were times in the two-hour and 39-minute 6-4, 6-2, 6-3 destruction of Murray when it was hard not to draw still another harsh comparison.
The Serb stepped out of himself to embrace his nation's cause in the famous old world competition and, we are told, was hugely rewarded by the experience.
Murray, on the other hand, expressed no interest in renovating the British cause. He had his own programme, his own priorities, and they were written in the unyielding stone of personal ambition. Fine and honest, if you like, but if anyone looked in dire need of contact with a wider world than the one supplied by his sternly intent entourage in Rod Laver Arena yesterday it was surely Andy Murray.
He smiled once – and also stuck his tongue out gleefully – when a winner went in, long after, it seemed, the issue had been settled, and the gesture appeared oddly manic. It was one of someone who was not getting a whole lot of joy out of what he was doing.
Where does he go now? Back into the old routine no doubt. It is one in which, after all, he is plainly equipped to prosper for as long as he likes and yesterday's pay day of more than one million Australian dollars was perhaps not an invitation for him to beat his breast and ask where he had gone wrong.
But what is most impressive about Murray is his great ambition, however skewered it may appear at this moment, to be one of the winners. Vast fortunes, we know, are available in the margins of big tennis but Murray for some years now has set his sights a lot higher than this.
Infuriating both for him and his warmest admirers is the fact that he has the game to support such a yearning. Unfortunately, it is not the one he has brought to three major finals now; or at least it is not the one it might have been if he truly stepped back and took an unflinching look at himself.
Sooner or later he will have to review his performance yesterday – and in all its gory detail. He will have to study all the times he lapsed into what seemed uncomfortably like self-pity.
He will also have to dwell on those moments in the first set when he had plainly planted a few seeds of disquiet in Djokovic, only for them to be blown away by his own inconsistency – and, not least, his failure to truly assert his belief that, somehow, he might win.
There is nothing wrong with losing a Grand Slam final, even three of them, if you emerge a wiser, more competitive young man. However, this isn't going to happen if you keep going over the old, futile ground. It made the rage of Andy Murray yesterday especially depressing in that it consumed him while he was pretty much standing still.