But as was not the case with Redgrave, the 35-year-old who steps figuratively ashore as the most successful Olympic sailor of all time - with four golds and a silver in a career which began at Atlanta 1996 - has another major competitive arena in prospect. Involving boats again, naturally – but much bigger boats.
Ainslie made his long-term ambition clear in January when he launched Ben Ainslie Racing (BAR), a team sponsored by JP Morgan, which is now taking part in the America's Cup World Series by way of preparation for an attempt to become the first British boat to lift the America's Cup itself.
And his official retirement today from the Games has only confirmed the hints he gave in the aftermath of his London 2012 victory, a culmination of what he called the "hardest couple of weeks" of his life. "You can never say never," he said, "but I don't think I can sail one of these again. It's killing my body so I don't think you will see me in Rio. But it's the best way to bow out at a home Olympics."
On the eve of the London 2012 Games I asked Ainslie about how he dealt with the contending demands of his Olympic and America's Cup ambitions.
"You have to be able to compartmentalise the different areas you want to focus on," he responded. "If I'm going racing the only thing I'm thinking about is that. I'm not thinking about the America's Cup or anything else that's going on in my life.
"The America's Cup is primarily all about the team, and the Finn sailing, although I have a great support team, is different. When I'm out there racing I'm alone, with full responsibility."
Twelve years ago, soon after Ainslie had won a gold medal in the Laser class at the Sydney Games and in doing so taken his revenge over Robert Scheidt, the Brazilian whose cute tactical moves in the medal race had earned him the Olympic title ahead of the Briton four years earlier in Atlanta, he took part in a mini race at the Royal Albert Dock which offered the press the opportunity to join in.
I was "crewing" on the boat skippered by another triumphant Olympian, Iain Percy, who had won the Finn class in which Ainslie now operates. The first mini-race was won by our boat, but Percy was confident there would be an immediate response in the next from the opposition boat skippered by someone he described as "the most competitive man in the world". And of course, there was.
As we spoke shortly before London 2012, I could not forbear asking Ainslie whether he concurred with his friend's sentiment. Well, he didn't disagree. But he made it clear again how mental compartments came into the process.
"I guess Iain knows me pretty well, better than most people," he replied. "I think sailing is the one thing in my life that I want to try and be the best at. There's nothing else in my life where I feel like I have to be competitive. Sailing is the one thing I want to be best at, to reach the highest level I can and to achieve things, so that's why I'm so determined to do well.
"I am competitive, but nothing like I am when I'm sailing. If someone beats me at cards, or my nephew beats me at a computer game or whatever it is, I laugh about it. I just don't like being beaten when I'm sailing, full stop."
And there, essentially, is the attitude that has got Ainslie where he is today.
He was only 19 in 1996 when Scheidt taught him that bitter lesson at the Atlanta Games – a lesson which was to prove invaluable.
The Briton lay in silver medal position before the final race, and after much pre-race manoeuvring the organisers put up the black flag - an indication that any boat jumping the start line at the next attempt would be disqualified.
"Robert was pretty cunning," Ainslie recalled. "Because he was sitting near the committee boat and must have heard them call out his sail number, that he was over the line, so he just sheeted in and started over the line with 10 seconds to go, knowing he was over it. When one goes, others go because they don't want to be given the jump. So about 20 boats went. I was among them and we all got disqualified and the net result was that Robert won the gold and I got the silver. Yes, in its way it was brilliant."
Four years later in Sydney the positions were reversed, and a couple of abandoned starts meant Scheidt was forewarned about the Briton's tactics. But he still couldn't stop him. Ainslie managed to get into a perfect spoiling position a matter of seconds before the start, and he soon isolated the Brazilian as the rest of the fleet sailed away, blocking his wind and weaving across his path. There was apparently plenty being said between the two boats.
In the end, Scheidt broke clear after ramming the Briton's boat, and then set off to try to catch the distant race ahead. Scheidt almost made it, taking advantage of a huge wind shift, but with Ainslie desperately catching up to see if more action was required, the Brazilian was penalised and the gold was secure with the Briton.
Bryn Vaile, who won gold for Britain with Michael McIntyre in the Star Class at the 1988 Seoul Olympics, has had close hand experience of the nitty-gritty of competitive action on the water for 30 years as a sailor and national selector.
"You can effectively stop an opponent by sitting in their wind," says Vaile. "It is called covering. It was originally introduced as a defensive measure, but what someone like Ben does is use it as an aggressive tactic. It's aggressive covering, if you like. You use the rules aggressively, rather than defensively.
"It's similar to the kind of manoeuvring you can get in Formula One. There are times when Ben's objective is to manoeuvre things so that he gets to cross the line ahead of a particular opponent.
"When Ben went to his first Olympics in Atlanta in 1996, the Brazilian, Robert Scheidt, made sure he got gold and Ben got silver by using that tactic. Ben didn't forget that. And when they were at the Sydney Olympics four years later, Ben replied in kind – and did it better.
"Ben's friend Iain Percy, who has won Olympic titles himself, describes him as 'the most competitive man in the world', and I know what he means. There is something of Ayrton Senna, or Michael Schumacher, in him."
That is, greatness.
Mike Rowbottom, one of Britain's most talented sportswriters, has covered the past five Summer and four Winter Olympics for The Independent. Previously he has worked for the Daily Mail, The Times, The Observer, the Sunday Correspondent and The Guardian. He is now chief feature writer for insidethegames.