Probably, they are right, but try telling that to Carson. "So I'm going to be 54 in November. So what," you can imagine him saying.
Time waits for no athlete, and by his own marvellous standards - last season Carson brought in a century of winners for the 23rd time in 25 years - the total of 52 recorded before Meshed lashed out at him had already prompted thoughts of retirement.
That the splendid veteran might easily have lost his life in the Newbury parade ring adds greatly to the concern raised by a bad fall at Newmarket and quite startling errors in riding.
We can be sure, however, that any attempt to coax Carson out of the saddle would be an ear-burning experience. What we are talking about here is not so much a driven man as one trying to fend off the curse of anticlimax.
Carson knows that, no matter what the rest of his life holds, he will never find more joy than he has had from race riding. "There is nothing better in football than playing," Bill Shankly said.
In retirement, one of the greatest baseball players in history, Mickey Mantle, said: "I loved it. Nobody could have loved playing ball as much as me. The hair comes up on the back of my neck when I think about it. I get goose bumps. And I remember how it was and how I used to think that it would always be that way."
It passes so quickly, you see, the cheers like thunder, the dark devil's wine of fame. Then it's over and they can't believe it's done. Long after the performance, when the old players think seriously, they realize that they have become obsolete at an age when most men are moving towards their prime.
Better to hang on than step out too soon? Maybe, but the onset of nostalgia is inevitable. At the passing of an old footballer whose later life had been filled with memories of the long ago, someone wrote: "He didn't die this week. He died on the day he had to stop playing."
That is the land of lost content, I see it shining plain,
The happy highways where I went And cannot come again.
A E Housman
In their determination to hang on, some delude themselves. "If Danny Blanchflower is nearby when you get the ball, run past him," Matt Busby said to his players at Manchester United when it was obvious that the great career of Tottenham Hotspur's captain was almost over.
Blanchflower's brain was still sharp but he no longer had the legs. It turned out to be his last competitive match. "I think Tottenham acted prematurely," he said many years later. Pele was still strong and supple at 34 but, in 1974, he resisted the temptation of making a fifth appearance in World Cup finals. "Nobody loves football more," I remember him saying one night in Brazil, "but another World Cup is too much."
A couple of days after Ray Wilkins ceased to be the player-manager of Queen's Park Rangers, he turned out for Wycombe Wanderers. At 40 years old, Wilkins simply cannot give up playing. Stanley Matthews turned out for Stoke City at 50, Billy Meredith for Manchester United at the same age.
Last week, Graham Gooch, 43, was named batsman of the year. "Nothing much has changed," he said. "It's still me against the 11 guys who are trying to get me out."
The sadness in all this is when you see a great figure reaching forlornly for what used to be. Usually because of financial imperatives, it often happens in boxing. Terry Downes was once asked how it felt to defeat Sugar Ray Robinson, who is regarded as the greatest fighter, pound for pound, in history. "I didn't," Downes said. "I only beat some guy who called himself by that name." When Robinson lost to Downes, he was 43 and in serious financial difficulty.
Similar circumstances forced the former world lightweight champion, Ken Buchanan, to take a contest in London against an opponent he could once have beaten blindfolded. Buchanan lost on points. "Just one more time," he said in the dressing-room afterwards. "Just one more time."
Whether Carson chooses to continue may depend on the medical advice he is given. "I think that Willie's time has come," somebody who knows him well said this week. "He should give it up. But the tough little sod thinks probably that he can go on riding for ever."