How do you tell someone you have AS?
If you missed out the word "probably" when saying that to an NT, they would immediately dislike you. Why? Simple, because they decipher it as you are bragging that you are rich, the same as Bill Gates is. NT's are strange creatures, they always jump to conclusions, especially if they are on one of their ego trips.
You're probably right. It's funny, actually, there's a boy in my school, who's in a significantly younger year than me and who dosen't really know me at all, who keeps saying I'm rich. I honestly don't understand why.
TBH, though, if he was right, I wouldn't complain at all
I don't know what the best strategy for you would be, I guess it depends on your style and what you are comfortable with.
But I will say, it's really important that you do find a way to tell people in your life, especially if you are dating someone. As someone who dated an NT, it would have been a lot easier if he'd been honest with me about it or open to discussing it. My advice would be not to tell someone immediately, wait a few dates. If it causes any sort of problem or misunderstanding prior to that than take that opportunity to explain it. But once you are sure you are with a partner who is an understanding person (or hope they are within several dates) you should tell them, it explains a lot. NT's do have very noticeably odd behavior to non-NTs and they might interpret certain things as you not being interested. It really helped to know what was going on and to thus be able to look at things in context. If you are with the right person, they will be open to learning and understanding about it. If they are, help them to see your perspective by explaining your experience and helping them understand. If they want to know, it's because they care, not because they are going to judge.
Usually I don't say that I have Asperger's (few people know, what Asperger's is, and this will lead to long explanation). But I tell about some of my traits I want people to know about, when they talk with me. For example, when I am new in the group of people, I notify them, that it's difficult for me to remember faces and names. Or that if I do something wrong, the best they can do for me is to say me directly about this, because I don't understand gentle hints. Or I explain, that when I don't express feelings, it does'n mean, that I feel nothing. So I prefer to notify people about particular traits important for current situation.