It may be that finally we are nursing an illusion today in this Gloucestershire valley where epic performance for so long has been routine.
But then who really cares if the third staging of Kauto Star versus Denman here so warms us against the chill coming down from the hills, if we can have it in our minds and our hearts for one more day?
The most brutal assessors of all, the bookmakers, are certainly not mincing their odds.
They have defending Gold Cup champion Kauto Star rock-like at odds-on and Denman drifting to maybe as high as 6-1, rather like the Marie Celeste, as one saddened observer put it on the eve of the steeplechase which again rivets that part of the nation which understands that what happens this afternoon is the greatest test of jumping talent racing has ever devised.
The truth, whatever the weight of hard-eyed professional opinion, is that as illusions go, this one is magnificent. It is one of those that draw us to everything we hold most precious in sport: supreme ability and an unblemished honesty of spirit.
This one has Denman, a beast of a hero in 2008 and an astonishingly brave second last year to the virtuoso Kauto despite a bout of illness that would probably have killed a lesser animal, finding once again a force which, whatever happens today, will always make him a legend of strength and courage in a sport where these qualities are generally seen not so much as marks of distinction but basic credentials.
It has Kauto the bewitching star, the counter-puncher of sublime timing and heart-stopping turns of speed.
Kauto just happens to be celebrating his 10th birthday today, the same age as Denman, and many of his supporters see this as still another omen, one to place alongside the fact that Denman last month at Newbury, and in the company for the first time of the great rider AP McCoy, showed to at least some critics signs of irreversible decline when he crashed out of the Aon Chase three fences from home.
Some, though, chose to blame McCoy, 14 times champion jockey, winner of 3,000 races, and this only adds still another dimension to the case that the Denman show is indeed drawing to a close. It's a human one as fascinating as any great prize fight because no two jockeys could be categorised with such sharp emphasis on their differing techniques, stylistic divides as profound, in their way, as though drawn before Muhammad Ali upset George Foreman 36 years ago.
McCoy is the supreme driver, the man who wants more from a horse than any man alive except perhaps Lester Piggott. When he was thrown from his mount Jared in yesterday's first race there was a great communal gasp, and then a high murmur of concern as he lay on the turf.
Inevitably, though, he was soon on his feet. "Jesus, your man is made of concrete," said an admiring compatriot of the man from Co Antrim, but there, is blasphemously, a strong view that master trainer Paul Nicholls, who is contending today to fill the first two places with Kauto Star and Denman for a third straight Gold Cup, may have made his first critical error in appointing McCoy.
"He would have been better of hiring someone like Barry Geraghty," said one racing insider. "McCoy is a great rider, everyone knows that but there is something about him which does not feel right when applied to Denman. There was never a horse that gave more than Denman, who was so willing, and the trouble might be that when you place on top of that the extra demands of AP you might be courting a complete breakdown.
"We worried that Denman was finished before he produced that brave run last year. Now Newbury has re-awakened those fears. Maybe Denman will be asked to do more than he can deliver tomorrow."
It is a haunting concern, no doubt, a possibility that cannot be removed from a race which offers two sensational possibilities. One is that Kauto Star will confirm his status as the modern Arkle, as opposed to the eternal Arkle, and sweep away the last of Denman's extraordinary resolve under the beautifully soft and intuitive touch of jockey Ruby Walsh's hands.
The other is that Denman, with McCoy's ferocious help, will come back again, not, like Kauto, throwing brilliant feints and surges but seeking to grind away the soul of even his most gifted competitor. It is a prospect guaranteed to bring a shiver of anticipation to the hardest man.
If the horses are quite separate personalities, so are their pilots. Walsh is a coaxer, McCoy a coercer. Kauto is an extrovert, a French-born gallery-player who was recently described by a stable girl at Nicholls' Somerset stables, as a "real French poseur. He just has to see a camera to pull a pose." Lucinda Gould added: "At home they are almost like brothers. When Denman wants to talk to Kauto he just walks over to the grille that separates them and gives it a few taps. Kauto sometimes does the same. But the strange thing is they could hardly be closer here."
Today, ironically, they divide the nation as they pursue the knockout blow, an almost certainly decisive win after last season's levelling of the score by Kauto, who also won in 2007 when Denman was still completing his big-time education.
If the boxing metaphor does hold, and you have to say it does because the balance of talent and power and character, if not today but certainly in their previous engagements, has touched a competitive perfection.
It was the same when Ali beat Joe Frazier in their third fight in Manila, when the score was 1-1 and Ali later confessed that he had never felt so close to death. That may be an unwelcome allusion here before a race which carries risks all of its own but it is one not so easy to avoid.
Not when you delve into the heart of this contest. It may prove an illusion, at least in some projections on the narrowness of the verdict. But there is nothing fake in its hold on the senses. Certainly, there remains one glorious reality. Kauto Star and Denman are still asking us to believe in magic of the most superhuman kind.
Each day of Cheltenham, Totesport is donating a £100 bet, and paying the winnings to a charity. Today's punt is from Bob Champion. The 1981 Grand National-winning jockey goes for Imperial Commander each-way in the Gold Cup. "He's the value. You'll make as much if he's in the frame as backing the first two to win."