Some people are under the impression that if someone avoids eye contact, they must be a sociopath. I find it difficult to make eye contact when I'm talking to other people, because it makes it really hard to focus on what I'm trying to say. Other behavior set of alarm bells in people's head as well, such as rocking back and forth. I try not to do that in front of other people, but sometimes, I'll start doing that without realizing I'm doing it.
I know that people think I'm weird, and some people are discomfited by it. I'm pretty much always nice to people. I actually tend toward "too nice," to cover up the gaps in my social skills. Some people are still put off by me, and very few people have any desire to pursue friendships with me. The few friends I have are all pretty strange themselves, in one way or another. The same goes for the romantic relationships I've had. People who are truly normal generally don't want to be bothered by me. At best, they make friendly small talk with me when I'm the only adult to talk to in the room. As soon as someone else comes in, however, they'll turn all their attention to a conversation with that other person, and find some way to shut me out of the conversation. Whenever I'm in an odd number group of people, it's almost guaranteed that everyone else will break into their little conversation pairs, and I'll be the odd one out. Any friendly attempts I make to join the conversation tend to be ignored. I act as nice and normal as I'm capable of acting, and most people still don't want much to do with me.
Thus, I wouldn't be so quick to assume that the OP was acting "like a douche." None of us were on that date. For all we know, the girl was put off by a mere lack of eye contact. There's not too much that can be done about that. Some people are put off by any differences. Unfortunately, describing AS won't help much. Some people still don't understand what AS is, others are laboring under the misconception that people with AS are essentially robots in human form, devoid of human traits such as emotion, humor or empathy. Thus, pulling the AS card isn't likely to help much. Your best bet may be to gravitate toward people who are somewhat "different" themselves in one way or another, as people who are a little odd themselves are less likely to be put off by differences. Unfortunately, that's the best advice I can offer, as I haven't managed to crack the code to social success.
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"And I find it kind of funny, I find it kind of sad./ The dreams in which I'm dying are the best I've ever had."