Lots... big things and little things. Too many to list here. It's going to be a long read
As a small child, no speech delay, but a lot of social and behavioural problems. No pretend play, liking soft toys for their feel, not to play with. Having frequent meltdowns, once hitting a teacher and another time ending up in emergency. Refusing to wear certain clothes, hating clothes with elastic, refusing to wear dresses, only jeans and T-shirt. Having obessions with things like Sellotape, wanting the same story read to me over and over again, listening to a song over and over again. Lots of quirks like eating every single morsel on my plate so it had to be totally clean. Refusing certain foods for sensory reasons, like tomatoes and eggs.
Refusing to do certain things at school, like country dancing and cursive handwriting. Not understanding social necessities such as apologising, simply not seeing or understanding the need for them, so refusing to do them. Intense likes or dislikes that I couldnt explain, such as disliking teenagers and sardines, but loving space, the solar system, astronomy - our teacher gave us a lesson on the sun, and I was hooked.
Happy to play on my own, wanting sometimes to play with others or to have friends, but not knowing the rules and not knowing how to go about it, or why things were going wrong. Very aloof, not wanting or giving hugs or affection, not sharing, talking about my day at school, refusing to hold hands to cross the road. I also had some ADHD-like symptoms, such as being extremely messy and untidy - putting my clothes on inside out or back to front so my mum had to actually check me before I left to school, and this was in middle school, at an age where kids generally were expected to be able to dress themselves without such problems. Constantly moving or fiddling, suddenly getting excited and rushing to one end of the room to the other when someone was talking to me. Restless and easily bored, always needing to be occupied or doing something. If I wasn't doing a 'special interest', I was bored.
Getting behind at school, getting very bad reports for a couple of years to the point where the school called my parents and told them that I need to go into a slow learners' class, which my parents refused to let happen, insisting that I was intelligent, but just not applying myself. Autism was suspected by the remedial teacher I had, but my GP didn't think I had it, only kids with the more severe symptoms of classic autism were diagnosed in the early 80s with very few exceptions.
As a teenager I became very withdrawn, a high achiever academically but very dreamy and in my head all the time, very aloof. The other kids all formed friendship groups, but I didn't fit in. I was rarely invited to parties or included in anything. I would sit with a group of girls, but not talk and not able to join in the conversation. It felt like watching TV. I felt isolated, detached, not a part of things. I deliberately read a teenage magazine, Jackie, to try to understand teenagers and their relationships better. I tried and experimented with different ways to talk to people or make friends, something that came naturally to other teenagers. I was very much aware of my social difficulties and differences to my peers. Became depressed, hardly spoke for 6 months. I had routines I had to maintain, such as eating my dinner at six o' clock and if it was even 5 minutes late, I started to get exremely anxious, if it was very late I would be upset or even have a meltdown. Getting up half an hour before everyone else so I could sit and eat breakfast in peace, without my other family members. Coming home and immdeiately locking myself in the bathroom for an hour to have a bath with a book and be alone. Self-loathing, I wanted to get away, wished I was somewhere else, and became obsessed with Germany and the German language after I watch a video showing a dark forest and mountains of Germany, this had an intense appeal to me for some reason. That's all I could think about for a long while. I was never happy and thought I could be happy if I went there.