I always had problems with social conventions. The rules, that everybody seems to know instinctively and did not need much of instructions. Others always knew, how to react in most situations, when I was usually lost.
I was lucky to have parents, that would explain most of the social rules, as they realized, that I am going against them. They never assumed that I would know them by myself, and I am grateful for that.
But they were not be able to be there every single time.
I remember the time in the fourth grade, when somebody from the nearby school started to spread rumours about me. Not only did I not know, how to react, but I was surprised that my whole class practically turned against me, and believed the rumours.
I asked years later, why was that. They told me, that the students were not supposed to get that well with the teachers and so I was singled out. It was the first time somebody told me, that there is a difference between students and teachers. Apparently the people just know, to treat the two groups separately.
I continued to high school, and after a couple of months I was told, that apparently I have to learn the names of every classmates, even if I do not speak with some of them at all. I am not allowed to cry in the middle of the lesson (really, nobody gave a good explanation for that one). I have to stop with presentation, if the blood starts falling from my nose (like I can't speak with the handkerchief on my nose) and apparently not making small talk every break makes me a scary person.
No, I did not know how to make small talk back then, and I do not now. I mean, there are so many subject, that are not allowed in small talk, and the discouragement from debates, not to mention, apparently a person is not allowed to say he or she is bored. They are supposed to politely redirect the conversation or excuse themselves. Does anybody every mention, how to do that? No.
I think that was mostly the reason, why I had social anxiety for years. People are just so unpredictable and illogical, and they expect you to know their rules without saying them.
Through some trial and error, making hypothesis and doing experiments, I managed to get the basics down. I can not successfully play the 'normal' human. But they are not a lot more understandable to me, than they were back there.