Scotland's greatest Olympian (aged 10)

AS A schoolboy with a passion for cycling, Chris Hoy was asked to set himself a long-term ambition. He wrote: "Become Olympic champion."

Yesterday, he surpassed even his greatest expectations, becoming the first Briton for a century to win three golds at a single Games.

His journey from schoolboy with a dream to Scotland's greatest-ever Olympian is an inspiring story of perseverance and self-belief.

It is a journey that has led him to huge successes in Beijing, capped yesterday with victory in the men's individual sprint at the Laoshan velodrome – the culmination of a 25-year cycling career.

On a day Britain's sportsmen and women increased their gold-medal haul to 16 – the best for 100 years – and Hoy secured his fourth career gold, he could not hold back the tears.

"It's the most unbelievable feeling," he said after defeating team-mate Jason Kenny and embracing his parents, Carol, 60, and David, 62. "You cross the line and all the pressure and expectation evaporates, and it's like nothing else you've ever felt.

"It's about the process and the performance, breaking it down to the technical elements. That's why the emotions come out at the end – it just erupts out of you."

For a man whose prowess at times seems otherworldly, it is fitting that Hoy's first exposure to bikes was during Steven Spielberg's blockbuster movie E.T. As a six-year-old, he was transfixed by the film's BMX scenes during a trip to the cinema.

His mother, a former sister at Edinburgh Royal Infirmary, later bought him his first BMX at a jumble sale for 5. Stripped down by his father, sprayed black and adorned with stickers reading "The Real McHoy", it did not last long, the frame snapping after a month thanks to Hoy's determination to jump off ramps. Its replacement – gifted to him by a neighbour's daughter – was broken, too.

By the age of seven, a hobby had become an obsession. With a Raleigh Super Burner costing 99 – Hoy and his parents paid half each – he came second in his first BMX race and joined the Danderhall Wolves club.

Soon, he had raised enough money to buy a Silverfox, and began racing with a team affiliated to Scotia BMX, a bike shop in Edinburgh. Father and son travelled thousands of miles, racing as far afield as Bristol, Crewe and Preston.

David Hoy, a surveyor, says his son's achievement is just reward for years of sacrifice. "He has, from an early age, been heavily into cycling, at the expense of going out with his mates," he said. "He drinks orange juice and goes home early. That makes him sound boring, but he's not. He just sets himself a goal and goes all out to achieve it."

By the early 1990s, Hoy was contesting races all over Europe. He was ranked No 1 in Scotland for five years – he also reached No 9 in the world.

The BMX boom, however, was nearing an end.

Aged 14, Hoy was a pupil at George Watson's College in Edinburgh, for whom he excelled at rugby and rowing, winning a British championship silver in the junior coxless pairs. Frank Gerstenberg, the school principal during Hoy's time there, said: "Chris was a superb all-round athlete – but cycling was what really caught his imagination."

After BMX, Hoy turned to mountain biking.

It was while with the Dunedin Cycling Club that he was asked to describe his ultimate goal in a training diary, and he wrote the three words that were to drive him to Olympic success.

The club's real importance came courtesy of its sessions at the Meadowbank velodrome. His first pedal strokes on its smooth boards came in April 1991. "Scared" and "intimidated" by the open-air track's steep banking, he began racing the 500m handicaps on Tuesday evenings, starting with a lap advantage over the older racers, gradually improving his times and switching to the City of Edinburgh Racing Club, which specialised in track racing.

Hoy won Scottish and UK titles, before, in 1999, taking silver in the team sprint at the world championships, repeating that feat a year later and again at the Sydney Olympics. In 2002, he took gold in the kilometre time-trial at the Commonwealth Games, then won gold in the kilometre sprint at the Athens Olympics in 2004. He now has nine world championship titles and four Olympic golds.

The Scot, who earns only 24,000 a year through lottery funding, is expected to head east to Japan to bolster his finances. He has been invited to compete next month in a keirin series, in which six to nine sprinters take part in a race with a paced start. Japan's betting industry means riders can earn up to 50,000 over just a few months.

• Glasgow City Council's purpose-built velodrome for the 2014 Commonwealth Games is to be named in Hoy's honour.