I’ve worn glasses since I was four and my school photos tell the story of my confidence. The glasses got bigger and bigger. By the end of my school career, I looked like Deirdre Barlow from Coronation Street. I needed something to hide behind.

My secondary school, Cliff Park High in Gorleston, near Great Yarmouth, was very sports orientated, which made me even quieter. I have hyperextended arms, which means they extend beyond the normal range. As a result, I couldn’t throw a ball straight, so I was never picked for any sports team. I was the geek with big glasses and a violin.

At 13, I was awarded a place at Junior Guildhall (specialist Saturday school run by Guildhall School of Music and Drama), which meant travelling from my home in Norfolk to London every week for extra music lessons. It was an eye-opener. For the first time I met other teenagers, like me, who didn’t fit into a neat box. I realised that collecting my mum and dad’s Readers’ Digest CDs because I wanted to hear Renee Fleming and other incredible opera singers wasn’t as weird as I thought it was. I liked contemporary music like The Cure and House of Pain, but I learnt that listening to Ella Fitzgerald was OK, too.

I tried hard at school, but I lost focus for a while when I joined Junior Guildhall because all I wanted to do was music. Mr Pursey took me under his wing. He was a big Welsh guy with a booming voice and was considered cool because he taught maths and ran the sports teams. He commanded respect from all the pupils, even the tough boys.

Mr Pursey lived two doors down from us, so when I started to struggle with maths, my parents asked him to give me extra tuition. He took the mystery away, took maths beyond numbers on a page. Suddenly, it all started to make sense.

Looking back, it’s ironic that I struggled with maths because I’m now studying astronomy and I love figuring out the maths behind that, but it’s not until someone speaks your language that it finally clicks.

When I was studying at the Royal Academy of Music, I gave piano lessons and taught at stage schools to earn some extra cash. If a student didn’t understand something I saw it as a reflection on my ability as a teacher. I’d try different approaches until I found something that made sense to them, like Mr Pursey had done with me.

Geek chic may be “in” now, but being different wasn’t fashionable at secondary school. When my sister set up a tuck shop, making her the most popular girl in the school, I started the “planets” club. When everyone was buying Nike holdalls, I had a flowery tapestry bag. And when everyone was straightening their hair, I had a perm.

I was the leader of the school orchestra, which was not cool because you had to sit at the front and play in assembly and the guy I fancied sat right there. I put my hair in front of my face in the hope he wouldn’t notice me, then everyone would laugh and say I looked like Slash from Guns `n’ Roses.

Although he was never my teacher at school, Mr Pursey looked out for me. He understood that I was different from the other kids. When I saw him, he’d give me a reassuring look or a smile and I’d feel OK about being me.

Myleene Klass is a singer and TV presenter. She is the ambassador for Casio Music, which is donating 66 digital pianos to secondary schools to promote music teaching. She was talking to Janet Murray.