"At the grassroots level you can go down to a sailing club and you can just get into a dinghy and borrow a boat or start sailing and crewing for someone else and get into it for very little money."
Ainslie's Olympic days came to a glorious golden end at London 2012, as he overcame what he thought were dubious race tactics to beat his rivals and claim the Finn Class title in the final race.
He accused Dane Jonas Hogh-Christensen and Dutchman Pieter-Jan Postma of teaming up on him, forcing him to do a penalty turn in race two, which left him trailing.
Ainslie went public with his displeasure. "They've made a big mistake," he told reporters, and promptly fought back to match the record for successive sailing golds held by the legendary Dane Paul Elvstrom.
"It was the highlight of my career and so special being in front of a home crowd and being my fourth gold medal," he said.
It capped a Games career which began as a teenager in Atlanta in 1996 where his "disappointment" at having to settle for a silver medal in the Laser Class gave an early glimpse of his burning desire for victory.
The 19-year-old Ainslie was edged out of the top spot on the podium by the hugely experienced Brazilian Robert Scheidt, but he was never beaten again in Olympic competition.
"It was a great achievement for my age but in a way something inside of me still wanted more and I guess that what's drove me on," Ainslie admitted.
By the time the Sydney Games came along four years later Ainslie was ready to take his revenge on Scheidt, relegating him to the silver medal position after a bitter and often controversial personal battle.
"I had an immense rivalry with Scheidt and I just managed to come out on top of that, and from then on really that gave me the confidence to come back each time and take the gold, and fortunately I was able to do that," he said.
After the Sydney Olympics he stepped up to the more demanding Finn Class, meaning he had to add nearly 20 kilograms of extra body weight to be competitive in his new discipline in a bigger boat.
"That was a big switch physically, I had to try and do most of that in muscle so I got into a lot of weight training and fitness training," he said.
"I guess it put quite a lot of load on the body as well and hence the back injuries which I started picking up later on in my career."
Those injury niggles were the result of hours of training in the gym and on the water, pushing himself to the limit in search of that fourth gold -- in front of fanatical home support at the southern coastal resort of Weymouth, where the sailing events for London 2012 were held.
"The pressure for London was like nothing else I've ever experienced, " Ainslie said.
A hint of the almost crushing weight of expectation came as he competed for a sixth world championship title in the Finn Class in Perth in late 2011, one of his last major competitions before London.
After finishing second in race nine of the event, Ainslie made the headlines for the wrong reasons after swimming over to a media boat and angrily remonstrating with the crew.
He felt they had impeded his progress during a downwind leg and his frustration boiled over.
Ainslie's subsequent disqualification was a bitter pill, but he later apologized for "overreacting."
Although injuries have taken their toll on Ainslie -- whose success at London 2012 earned him a knighthood from Queen Elizabeth -- he says that he has never lost his love for being on the water.