Your child knows they are different from other people. It’s pretty obvious. Not talking about it won’t mean they don’t notice the divide, and they know it *far* sooner than they talk…
What age is good for explaining? My son’s 4 at the moment, so I’m guessing we have a few more years. Will he ask? He still mostly repeats things (though he’s getting really awesome at using the things he repeats in context and as communication). I don’t know how much he gets from me right now, but I talk to him whenever he’s interested.
I knew when I was 3 that I was different. It was incredibly apparent to me just how much more trouble I had with things than most kids. So I don’t think it’s ever too early to just talk about things as they come up naturally. It doesn’t have to be a big dramatic deal. After all, it’s just everyday life to your kid.
But anyone who thinks that a kid doesn’t know just because they haven’t been told, has their head in the sand. Our pattern-recognition skills are fierce, remember.
I realized that I was different when I was three, as well. My realization that I wasn’t like other kids first came when I began preschool, and my memory of having made this realization is something that haunts me to this day. I don’t think that having a name for my difference (I mean, had I been diagnosed at that age) would have bothered me; in fact, it may have made me feel less confused. Though I’m not really sure if my three-year-old me would have understood what being “autistic” meant.
I was also in preschool. It’s one of my very earliest and clearest memories—watching this big group of other kids playing with each other, and having tried and tried and tried to join in, not knowing what I was doing wrong, and finally just stopping, and sitting back, and thinking in words I didn’t have yet, “they’re never going to let me in, and I’m never going to be able to make them. I’m never going to be able to be like that.”