Jane Fallon, executive producer Channel 4 was developing a comedy-drama series set in a school. It had a pilot script but it needed a more original angle. It offered me free rein, which was irresistible. I put together a team of young writers and we developed the idea into something that felt unique. In all the other shows I’d seen set in schools, the teachers were saintly and really cared about the kids, apart perhaps from one crusty, disillusioned old-timer. But lots of my friends had drifted into teaching after university: for them it was a job rather than a vocation, which was far more interesting. Our teachers were more like them. They were only a couple of years older than the kids, hated their jobs and were completely self-centred. On paper, Simon, played by Andrew Lincoln, was quite annoying because he was so desperate to be liked. I had worked with Andrew on This Life and knew he’d be perfect at bringing a sense of fun to the character. I was keen to have some new faces, so we cast extensively to find actors with chemistry. We based the cast, crew and offices in a disused school in Bristol. Once a parent turned up asking how they could enrol their kid for the next year. Channel 4 let us go crazy, which is why it got madder and madder, with things catching fire and a donkey wandering through the school. The joke was that the teachers were so self-absorbed, they never noticed anything outside their little group. It was so successful, Channel 4 commissioned four series in all. People really hooked on to the music, like the title track: Belle and Sebastian’s The Boy With the Arab Strap. I liaised with record companies and listened to all the upbeat indie I could find, and left a pile of CDs in the editing suite. It polarised teachers. Most liked being seen as real people, but others complained that teachers would never behave that badly, especially the smoking. That had come from me visiting my old school in Slough to remember what it was like. One of my favourite teachers was still there, now in her 60s, and still climbing up on the roof to have a sneaky cigarette at break time. She said: “You won’t tell anyone, will you?” I went: “No, no.” But I thought: “That’s going straight in the show.” Raquel Cassidy, played Susan There hadn’t been anything like Teachers before: a comedy drama with fantasy elements such as lions and penguins wandering about. Andrew Lincoln was like an angel. I’d never done TV before, so he’d have his hand on my back, pacing me along corridors and stopping me on my mark. The publicist said: “You’re going to be on billboards and it’s gonna change your life.” The script said: “Susan is just lovely.” I thought: “How can I be that? I’ve been totally miscast.” Susan cares about teaching but she loves smoking and drinking. We couldn’t drink alcohol at that rate and still manage to do all the different takes, so the alcohol was all fake, as were the cigarettes. I’ve never smoked an actual cigarette in my life. Real teachers reacted against it at first, but then people went: “Hey, teaching’s cool.” Apparently it led to this big surge in teacher training. Then the backlash became: “Real teaching is not nearly as much fun as you said it was.” I’m filming a new show with Greg Davies, who used to be a teacher. He told me that our world always looked a lot more fun to teach in than his reality. To date I’ve played four teachers, including Miss Hardbroom on CBBC’s The Worst Witch. You wouldn’t catch her with a cigarette, but going to work is much easier on a broomstick than sitting in rush-hour traffic. The irony is that I would make the world’s worst teacher– I don’t have an ounce of patience. I’d be like: “Why don’t you get it? I’ve told you once. That’s enough. Break time now.” It was such a gift to have Teachers as my first TV show. It was fun doing all these ridiculous things, like having my knees painted, trying on moustaches, and pretending to be a girly girl to impress another younger teacher my character fancied, and not being able to walk in heels. They put a real lion in the boys’ toilets. The penguins were super smelly and quite shy. If you’ve got penguins queueing up to act with you, you know you’re doing something right.