Jack McCaffrey, fizz-bombing across Croke Park, sirens wailing, tyres screeching, scorching down summer's highway, reminds us of a simple, intoxicating truth.
It is the one that announces speed - the rapid blur of movement rather than the amphetamine with which it shares a name - as the ultimate, mind-altering narcotic.
McCaffrey doesn't so much run, as detonate. He ignites, erupts, this Sky Blue ring of fire, as if fired from a magma chamber, as if he were a blood-brother of Vesuvius itself.
The rush and zoom of NFL running-backs entrances Don DeLillo in his novel End Zone.
"Speed," the author marvels, "is the last excitement left. The one thing we haven't used up, still naked in its potential."
DeLillo might have spontaneously combusted in a high of exhilaration watching the flying doctor hit Lear Jet torque in the seconds leading up to his goal for the ages last Sunday.
Croke Park was electrified: From the moment Brian Howard, dancing on draughts of air invisible to the naked eye, plucked Stephen Cluxton's kick from the stratosphere, McCaffrey was off and running.
Not running, but appearing, as if teleported by Scotty from the Starship Enterprise.
It is a thrilling jolt to the senses: Athlete as lightning bolt, a blinding flash of bright, coursing luminosity sweeping across the stadium, mesmerizing a mass audience.
McCaffrey delivered almost 80 minutes of vaulting ambition on the biggest day in the Irish sporting calendar.
With absolute, cloudless clarity of thought, he seized responsibility, scoring 1-3 from wing-back, the points divided between left foot, right foot, and fist.
Even in a house crowded by excellence - where Seanie O'Shea, David Moran, Killian Spillane, Stephen Cluxton, Dean Rock and Howard were all touched by the heavens - McCaffrey's masterclass stood alone.
In the gallery of transcendent All-Ireland performances, it ought to be framed alongside Maurice Fitzgerald's supreme 1997 exhibition of murderous elegance.
But if McCaffrey unveiled lesser known gifts with his two points from range, it was still his hitting of the afterburners, his breakneck moving though rush hour Croker traffic as if propelled by a freak fetch of wind, that seized the hour.
An eye-popping speedball, darting toward his destiny, overlapping Ciaran Kilkenny, presenting Niall Scully with the outlet of a zooming blur of killing intent.
Scully delivered a sumptuous, soft and perfectly weighted pass into McCaffrey's flight-path. The Hill 16-bound Clontarf bullet train devoured the ball without breaking stride.
His finish was a triumph of power, but more critically, exceptional technique. And a sort of ecstasy filled Croke Park, a did-that-really-happen gasp of wonder.
This is what speed does. Those of us who have been fortunate to be in the arena on one of those nights when Usain Bolt scorched the earth, or Katie Taylor's fists danced a too-fast-for-the-naked-eye jig, or Keith Earls located that gear not available to mere mortals, or Ruby Walsh came galloping up the Cheltenham hill on some flying machine, or DJ Carey laughed at the speed limit, had known the sensation before.
But the thrill of seeing an athlete surge as if fired from a Cape Canaveral launch pad never ebbs.
Something unique happens almost every time McCaffrey gets the ball with open road ahead of him.
An audible ripple of anticipation/panic - depending on your allegiance - rises up and consumes Croke Park, fuelled by an expectation of rapid, devastating movement.
Mayo were able to contain McCaffrey in the All-Ireland semi-final through tactical cleverness and the magnificence of their own winged chariot, Patrick Durcan.
But last Sunday, McCaffrey was uncontainable, almost liquid in his graceful ingesting of space.
It felt like a contest of unequals: a flying Pegasus against flailing, thrashing earth-bound steeds.
It felt, in DeLillo's words like the "last excitement", a sight so intoxicating that you would trade every early possession for one last glorious fix.