Yeah I had an occasion when I thought a nice person with Asperger’s was being deliberately horrible, because I didn’t know.
Basically was out with a friend in London, and we unexpectedly bump into an old friend of hers who doesn’t live in the UK. We were on our way to have some dinner, so we invite this friend too, who was really friendly to me. In the restaurant though, this person acts like I don’t exist, talks over me, keeps taking the conversation back to places and people I didn’t know, the sort of thing people do to really make it clear they don’t want you there. I thought “wow, why do they suddenly hate me so much?”.
Brought it up with my friend later and she said “oh, sorry, they’re on the spectrum and really bad at group conversations, I should have said”. So what was coming out as the standard behaviour for showing you hate someone and wish they would leave, was actually “food + noise of other customers + old friend + new person = too much all at once, better concentrate on one or two things at a time”