As I held a corner of the Olympic Flag that special night, I declared: "In the name of all the competitors I promise that we shall take part in these Olympic Games, respecting and abiding by the rules which govern them, committing ourselves to a sport without doping and without drugs, in the true spirit of sportsmanship, for the glory of sport and the honor of our teams."
It was a magical moment to say those immortal words at the Olympic Stadium in Stratford in front of 80,000 spectators and a worldwide television audience of around 900 million.
Unfortunately in the London 2012 taekwondo competition, I didn't manage to repeat my Olympic medal-winning performance from Beijing 2008 but I will still never forget what an amazing and inspiring few weeks those Games were; not just for me and all the other athletes, but for the whole of the UK.
The really important thing now is that we continue to build a real legacy of sports participation from the London 2012 Olympics and Paralympics, particular for young people.
As one of Sport England's Sporting Champions, one of my roles now is to meet with young people to inspire them and motivate them and I will be looking to do exactly that later this month at the Sainsbury's School Games in Greater Manchester.
The event is something that I'm really looking forward to, not least because it will be taking place at the superb Sportcity in Manchester, which is the location where I spent a lot of time training in my bid to become one of the world's best athletes in my sports.
The Sainsbury's School Games is backed by crucial National Lottery funding from Sport England and designed to increase the opportunities for young people to take part in sport across the school year. It is also an event that allows them to give their best in the sporting arena, make new friends and have lots of fun. At the end of the day, that is what sport is all about.
The concept of the Sainsbury's School Games takes me back to that Olympic Oath I made at the start of London 2012.
Although there are still some out there who struggle to see the huge benefits of participating in sport; it is in my mind unquestionably a force for good.
When taking that Olympic Oath, my words highlighted the importance of abiding by the rules, of being committed, of not cheating and of competing in the true spirit of sportsmanship.
These underline the three Olympic values of friendship, respect and excellence.
These values are something that all young people should strive for both in sport and in life.
By doing so, they will keep Olympic Flame burning brightly and the inspirational legacy of London 2012 very much alive.
Sarah Stevenson is a British taekwondo athlete who won a bronze medal for Team GB at the Beijing 2008 Olympic Games. At the London 2012 Olympic Opening Ceremony, she was chosen to take the Olympic Oath on behalf of all the athletes competing. She is also one Sport England's Sporting Champions that will attend the Sainsbury's School Games. To register a school for the Sainsbury's School Games click here.