I didn't really enjoy primary school. But I didn't realise that I hadn't enjoyed it until I got to Southend High School for Girls.
My physics teacher was Mr Betts. He joined when I was studying for my GCSEs and taught me for three years. Physics wasn't necessarily the most popular subject, and I wasn't mad on it either, but Mr Betts had this ability to engage everyone he taught. Such passion. Such enthusiasm.
Here's what he did, and this is what was fundamental: he let us ask questions. Sounds simple, right? He showed me that physics isn't just what's in a textbook. He was the first person to explain that we don't know everything and there are still questions - particularly in physics - that need answering.
He wasn't afraid to go off on a tangent. We once found ourselves discussing quantum universe, stuff about quantum particles, the sort of thing you'd never cover at that age, because we kept asking questions and he kept answering them. And it got to the point where he said: "You know what? I don't know the answer. Actually, no one knows. That's what we're trying to find out."
Thinking about it, that's why I made my degree choice [applied maths with elements of physics] at Oxford. It intrigued me, thanks to Mr Betts. It was him who encouraged me to apply to Oxbridge. He came to the school, saw something in me and pushed me. He encouraged me.
Mr Betts' class was wonderful. There were only eight of us and it was quite a high-flying set. Once he accidentally let slip that a new course we were studying was designed for girls. He had a class full of young women roaring: "We're studying physics for girls? What are you talking about?" But it was really just a course designed to appeal to girls, so I guess he had the right motives.
What was really interesting about Mr Betts was that he had been teaching for a very long time and yet he was still utterly obsessed and enthused about his subject. He was entirely on top of the latest discoveries. Other teachers stuck to the curriculum and we were bored year after year, but he went off on these glorious tangents.
Up to that point we had been taught that if it's in a book, it's right, and that's what you must learn to get the marks. But that's not always the case. I think it's kind of comforting to be told that not all the answers are at hand. I never properly understood certain topics and it was a relief to be told that was OK. Mr Betts also explained that theories previously assumed to be right could be proven wrong.
He treated us more like university students than schoolkids - we had the curiosity, enthusiasm and passion for the subject that he thrived on. I had other physics and maths teachers who were nowhere near as engaging. I was never interested in doing experiments that had been done a million times before with crocodile clips. But talking about how one particle on one side of the universe can influence another on the other side through quantum entanglement was much more interesting.
Rachel Riley was speaking to Tom Cullen. She will appear in a forthcoming episode of 24 Hours to go Broke, in which celebrities have to spend pound;10,000 in 24 hours in a random location. The series starts on 13 May on Dave
To sum up
Born 11 January 1986, Rochford, Essex
Education Thorpe Hall School and Southend High School for Girls, both in Essex; studied maths at Oriel College, University of Oxford
Career Television presenter who became co-host of Countdown in 2009. Took part in the 2013 series of Strictly Come Dancing