My various coming out experiences may be unusual in that none of them have required any explanation whatsoever.
First, my brother. Chatting about human sexuality, asexuality comes up, I mention that's me, he says "you never seemed interested in that sort thing." Main thing is, he already knew all about it.
Next, LGBT people. Me: "I don't lean in any direction; I'm ace." Them:"Cool beans, that guy's ace too, he did all these programs a few years ago..."
Later, random person talking about their relationship troubles. Them: "You know what I mean, unless you're asexual or something." Me: "Actually, I am." They were surprised that apparently most people don't know about it.
Again. Person: "This may be personal, but are you gay or straight?" Me: "Neither. Asexual." Them: "I knew it!" They win a five dollar bet that I am asexual or something. I get two dollars for existing.
Visibility seems to be one step ahead of me, and I have no complaints. Is this as bizarre as it seems?
I think I came out to someone who already sort-of knew about asexuality exactly once, which was all kinds of awesome. And then there was that time I came out in the middle of a classroom discussion and ran into another asexual, which again: all kinds of awesome.
In general, though, I usually get "what's that?" when I actually give people a pause to ask a question before I launch into the explanation. (My coming-out spiel tends to be the sentences "I identify as asexual, which means that I don't experience sexual attraction to anyone. Sort of like being the opposite of bisexual.")
I've definitely never had a random stranger peg me as ace, though. That's actually kind of freaking awesome.
The whole thing is awesome and bizarre and seems somehow rigged. It's especially great because I really dread the explanations, not being a verbally eloquent type. I really admire people who can make sense with ease when they speak spontaneously, but I am not one of them. I guess the downside is that I'm not getting any practice.