From making life hell for a young teacher to doubting the motives of a caring foster mother, Olivia Petter, Derek Owusu, Annie Lord and other writers repent for past bad behaviour

At school, I was not a good girl. Actually, that’s putting it mildly: I was an emotional terrorist hellbent on inflicting torture and humiliation on my year 6 teacher, Ms Hill, one whoopee cushion at a time. That’s how it began, anyway, but like all crimes, mine followed a strategic pattern of escalation, carefully executed alongside my best friend and accomplice.

Can a sentence affect the course of your life? Five authors reveal the interactions that transformed the way they saw themselves – and the world

When I was 14, I had to start a new school. I wasn’t great at starting new schools, even though I had done so quite a few times – once for my dad’s work, once because I wasn’t fitting in at my primary school and once because my parents didn’t like the teachers. Of course, 14 is possibly the most awkward of all the ages to start a new anything. Anyway, it was halfway through the first term at the new school in Newark, Nottinghamshire, and I was taken aside by my history teacher, Mr Philips, at the end of a lesson. He didn’t like me very much. To be fair, I was probably hard to like, from a teacher’s perspective. I had trouble concentrating, I stared out of windows, I clowned around. However, it is difficult to explain the shock to my self-conscious teenage soul when he told me, “I think it would be a good idea for you to join a special needs class.” Now, for context, the year was 1989, and in my state comprehensive at that time the idea of being “special needs” was akin to being given a leprosy bell or being marked with a cross for the plague. It was a binary system. You were either “normal” or you were “special needs”. To make matters worse, I was told that another teacher – my art teacher – had come to a similar assessment.