I was one of those kids who was really into sport from an early age. I did competitive BMX racing from the age of nine and sport played a big part in my school days. I was always the one organising games at lunchtime or after school. My nickname was “County” because I used to play county standard in everything I did.

When you are at school you moan about it, but when I look back I think it was the best time of my life. I was a bit of a prankster, but I never had a detention. I was naughty, but cheeky-naughty.

We had a lower school and an upper school and they were about 10 minutes apart. One day I wrote on the board in a classroom in the upper school that the class should go to the lower school. The teacher was running late and all her class walked over there. The other teachers just laughed.

Those school days were what set me up to become a professional athlete. You never know what would have happened otherwise, but I have fond memories of school. There were some subjects I didn’t like - I wasn’t very good at maths or the pressure of exams, but I look back on it and don’t know what I was moaning about.

There are two teachers I owe a lot to. I went to Hinchingbrooke School in Huntingdon (Cambridgeshire) up until my GCSEs, then my parents moved abroad and I went to boarding school - at Stamford School (in Lincolnshire). At Hinchingbrooke, Roger McGready was the one who really pushed me in the right direction. He said to me: “You can’t put in what God left out,” making reference to the fact I had talent. I have never forgotten those words.

Hinchingbrooke was really good for sport. It upsets me that kids don’t do enough PE now, but we had five lessons a week and every lunchtime we were kicking a football around. For cross-country runs we would go through woods and swamps for an hour, which was character-building, but you probably couldn’t do it now.

Mr McGready was one of those PE teachers who loved his job and was always organising things after school. He saw I had talent, although it wasn’t particularly athletics at that point, and pushed me.

When I got to Stamford, Kevin Johnston took me by the scruff of the neck.

I had done five different events at sports day and I ended up winning all five and broke five school records, so Kevin Johnston clipped me round the ear and literally dragged me to a sports club. He said the last time he saw talent like that it went on to get an Olympic medal. I didn’t believe him, but he took me to the county championships and then the English Schools Championships and I came second in the 400 metres. He was a great teacher and if it was not for him, I would never have become a professional sportsman.

I hope both teachers realise how grateful I am for their guidance.

Iwan Thomas is an Olympic silver medallist and is the reigning UK 400m record-holder. He is speaking at the Pavilion Tours Sporting Legends Convention, 6-8 June at Kingswood Grosvenor Hall in Ashford, Kent. For more information, visit www.paviliontours.co.uk. He was speaking to Nick Morrison.