A jolting realisation struck as Ronan O'Gara offered one irresistible flash of insight after another on Saturday: Here is the pundit that Roy Keane could have been.
And perhaps still could be.
Even on an upbeat, redemptive afternoon for Irish rugby, O'Gara, in civilian clothing, without ever leaving the Virgin Media TV studio, was the international who delivered the most compelling and riveting body of work.
His masterful trawl through his own playing experiences, the willingness to open the door on the monstrous insecurities that accompanied him onto the battlefield, sentence after sentence dripping with brutal honesty, gifted the audience a rare, access-all-areas pass into the soul of a wavering and vulnerable elite athlete.
O'Gara invited us to swim in the river of his old paralysing anxieties, to revisit a time early in his career where he found himself offering up novenas that Ireland would not score a try in a tight game.
Why? Because of his terror that he was not equipped to slot what would be a match-deciding conversion. The choking concern that with the game at his mercy, he might fluff his lines.
This was Ronan O'Gara, the unbending giant forged from mental steel, who, with the weight of the rugby universe on his shoulders, somehow summoned the nerve to conjure a Grand Slam-winning drop goal.
The icy assassin of our perception, the one we believed gifted a reptilian nerve by the Gods, admitting it wasn't really that way.
And now he was telling us that it was the very opposite, that early in his career with Munster and Ireland he had shit himself with panic and trepidation.
It made for mesmerising, beyond-all-spin television.
Brave and intriguing and perceptive, it confirmed O'Gara's position at the very summit of the mountain of former players who now boost their bank balance by talking about the games unspooling in what used to be their playground.
As ROG moved with astonishing candour along the entire bandwidth of his playing days fears, I couldn't help but consider the contrast with his fellow Corkman, the long-time lion of Old Trafford.
Like O'Gara, Keane is blessed with a mind that functions with uncommon and illuminating clarity.
Roy is clearly intelligent, he bleeds charisma, his achievements and his brooding personality offering him an unrivalled, box-office, stage-presence.
There are so many strands to his story: How he rose above teenage rejection to become a titan of the game; his relationship with two of the greatest managers football has known; the setbacks he endured as he sought to gain a foothold in the game; the competitive fury that was the fuel propelling his journey.
Keane, if willing, when he took his Super Sunday seat, to remove the padlocks bolting the doors to his own sensitivities, could deliver lessons as riveting as O'Gara.
What a shame then, that Roy has chosen to become a one-trick-pony.
A superior, often unmissable variant of that class admittedly, one who can still tower over his fellow studio guests, challenging consensus, cutting down the biggest names and setting Twitter aflame with one flourish of his scything tongue.
But, even on those days when his fellow studio guests look vaguely terrified to interrupt his rant, the feeling persists that he could be so much more than the perpetual and one-dimensional Mister Angry.
Why would such a multi-layered individual settle for being the reductive author of acerbic put-downs, the unsmiling Darth Vader who seems to regard it as his duty to play up to the forever unimpressed caricature?
It can be terrifically entertaining. It will, almost inevitably, seize the headlines.
But, in truth, it is Roy falling into a lazy trap, one for which any he would have savaged any guilty team-mate during his playing days of thunder: He is selling himself short.
Stopping short of being all he could be.
This from a Keane loyalist, one who so frequently felt a life-affirming surge watching the red or green shirted force of nature seize the very biggest stages.
Imagine Keane, as O'Gara did last Saturday, welcoming the audience into the dressing-room or out into the arena on a night with everything on the line.
He went there at times in his two autobiographies and in any number of unforgettable newspaper interviews.
But on TV, his obsession is the caustic punchline.
Keane is uniquely positioned to shine a light on the demons that might invade the minds of Kevin de Bruyne or Jordan Henderson or Paul Pogba.
Because he walked those same steps.
Were there days when Keane, like O'Gara, felt the suffocating presence of fear?
Or when, in a stadium filled by tens of thousands of paying customers, he felt terribly alone? If so, how did he rise above such anxiety?
As a manager who has known the darkest days, he could speak of the friendlessness, the sense of futility Ole Gunnar Solskjaer must be feeling as it dawns on him that the Manchester United story is close to ending in tears.
Because Roy was the skipper on his own Titanic.
Sadly, he rarely revisits those iceberg moments, the moments when a gash opens in the hull and when a terrible sense of powerlessness washes over.
O'Gara has spoken in the past of his admiration for Keane, of how he was inspired by his relentless striving for excellence.
Maybe the rolls have now reversed, perhaps Roy might be inspired to offer a little more of himself if he sat down and pressed the play button on Ronan's weekend masterclass in fearlessly introspective punditry.
Keane has all the required weapons for greatness, the shame is he chooses too often to deploy only the raging blunderbuss.