There has always been a touch of poignancy in Kevin Pietersen, a hint of insecurity even at his many moments of supreme triumph. Yet it seems we didn't know the half of it in his days of streaked hair and copious bling and batsmanship that seemed to come directly from the gods.
Today at Lord's, though, there will be the most powerful sense thus far of a greatly talented sportsman fighting for his professional life.
You know he has a crisis when Jonathan Trott, he of the batting rituals that brush so abrasively against eternity, tells him publicly that he just has to remember it is a simple matter of bat and ball. If only it was, Jonathan.
The Sri Lankans, so ravaged in their confidence at Cardiff, will certainly advertise the drama of one man's battle to believe in himself when they rush with indecent haste their slow left-arm spinner Rangana Herath towards the bowling crease almost the moment Pietersen walks through the Long Room to resume his ordeal.
Herath, of course, will have a little pressure of his own. Eleven years ago he was heralded as something of a sorcerer when his mystery ball confounded the Australians, but since then it has been mostly uphill work in the shadow of Muttiah Muralitharan. Now he might just have reason to believe he could yet be cricket's version of the man who shot Billy the Kid.
If it happens again as it did at Cardiff, when Pietersen was lured into an embarrassing and fatal lunge after his team-mates Alastair Cook and Trott had gorged so relentlessly on bowling that seemed ultimately benign, some might see not so much another damaging blow as a coup de grace.
Pietersen's Test figures are of course still imposing – 5,669 Test runs at an average of 48.04 – but running through them is the wound first inflicted by New Zealand's Daniel Vettori and now reopened by Herath.
In 61 Tests he has been dismissed 19 times by left-arm spinners. The fault line has never been more pronounced, as we saw recently when Cambridge University's Zafar Ansari did the damage.
After the Cardiff denouement, Pietersen seemed almost to be in denial, slipping lightly over his problem while preferring to speak of the pleasure that fills the heart of every member of the England team when a colleague performs stupendously. It is a joy, Pietersen went on, enhanced by the certainty that if it is Trott or Cook today, there is every chance that it will be you tomorrow. Maybe it is so, maybe not.
At the very least it is a reminder of the line that outstanding sportsman are obliged to walk every day of their professional existence. You listen to the jaunty voice – and the assurances of his coach Andy Flower and his captain Andrew Strauss that he is on the verge of a return to the heaviest scoring – and then you remember one of his quite recent forays into Test action.
It was in Adelaide in the second Ashes Test and his performance was nothing less than stupendous. He scored 227, hit 33 fours and a six, and he made it very easy to recall that over his first 25 Tests he was more productive than any other batsman except Sir Donald Bradman – and that his first thousand runs in one-day cricket tied the record rate of Sir Vivian Richards.
They will be numbers, though, just remote numbers, if he walks to the wicket today. He insists he will play five more years and score more than 10,000 Test runs. It is a reasonable demand on extraordinary talent and will remain so right up to the moment Rangana Herath attempts to remind us once again of the mysteries of cricket and life.