Thank you @TFImBackIn @ReleaseTheDucksOfWar
There are some things I can read that deeply affect people and think 'That wouldn't/wouldn't have bother(ed) me at all!' but I'd never think negatively of that person for it, as you've both said, people are very different. And children are people.
But no, it wasn't really 'one school move' by itself.
It was the knock on effect.
I already found school very overwhelming and tiring. I am a summer baby and an only child and I wasn't used to the dynamics of other children, I didn't understand the things they did or the games they played and the fact lots of them already seemed to know what they were doing and knew one another (I assume through older siblings, wider friendship groups etc). I did eventually settle in somewhat but it was a work in progress. I had a small group of friends, they are all still friends to this day and have grown up together. We'd sometimes play out or at one another's houses. My friend's mum used to look after me after school too as my Mum worked and she didn't. I was very close to my Mum and my friend and her siblings.
I was taken to a new place, and moved schools. There was no preparation for it, I was told on a Friday night that I would be starting on the Monday. I was terrified. I also had a realisation that I had nobody. If my Mum could do this to me, then it wasn't only my Dad who hated me.
My Dad was abusive, and my Mum worked long hours. I was now often alone with him now as nowhere near my friends. He was violent and aggressive and the move made him miserable too so he was worse. The school was huge compared to my old one. I was bullied for being 'quiet' and 'weird' and then kids found out about my Dad and bullied me for that. I began comfort eating and was three stone heavier within the year. So now the kids had something else to berate me about. I was stripped almost naked more than once. It was a long walk home and I'd be bullied on the way home too. I hated my body and didn't yet correlate food=fat, so I ate more and more and with hindsight was very addicted to sugar, it was the only thing I really had left that was pleasurable.
I did have loving grandparents. I saw one set often, one not so much. They noticed a change in me both physically and mentally and begged my parents to do something but they didn't, that is until the last 6 months of school where they reluctantly moved me to a different school. I sort of 'reinvented' myself here and made friends but that was very short-lived. I was massively overweight at this point, no real friends and still 'the weird kid' and that's never really left me. High school was much the same, I hung around with other outcast kids who were all under the radar somewhat. until I developed a different eating disorder. I became very underweight in my teens. I started drinking at the age of 12, probably in some effort to be 'cool'. I found it ironic that my Mum was now so worried about me being underweight when she'd also been so awful about my weight when I was overweight.
My weight has ruled my life since I was 7, now. On the plus side, as mentioned above, I am now a weight lifter and back in control. But I do wonder what a different life may have been like if someone had have paid any mind to me in childhood.
My friends from my original school are all still tight-knit. We msg very occasionally but that's it. Around ten years ago, the friend whose mum used to look after me died tragically. It was bittersweet seeing my old friends all together and their closeness! I was mentioned at the funeral by her brother who wrote the eulogy as being 'their honoury sibling' which was nice.