LOL. Yes, I think that is just it. It's the vicarious impulse in parents to over-identify, or at least assume that anyone who
might be overstating their kid's ability is doing so. We may be extra sensitive to this because of the frequent (over the years) accusations of helicopter parenting borne of our need to be involved to manage DD's (life-threatening) medical issues.
It's rhetoric which stops
just short of;
"Huh. Well, I've seen your kid. Your kid doesn't seem like such a freak to me."
Gee--
Thanks?? 
If I'm honest, I've actually heard that statement from some people over the years-- and I'm less offended by that one, honestly stated, than I am about the sort of sly "because she's not that weird, it must be YOU, not her" (in spite of any evidence to the contrary). The honest statement
is a compliment, if an awkward one to say to most parents. That one is related to how 'well-adjusted' our kids are. THAT is a statement that I
will take credit for, because I do feel that we've had a lot to do with that one. It's the 'you're making it up somehow' vibe that rankles.
I'm kind of wondering-- at what point does this nonsense stop? DOES it stop??
That is, will my DD as a college graduate still be hearing "Oh, but you're
really just a high school kid," from some insecure person?? "Oh, but you
really just a college kid..."
Sometimes I just want to get her a teeshirt that says "I'm probably smarter than you, but I'm also good at not making YOU feel awkward. If it doesn't bother ME, why should it bother YOU??"
It's very peculiar that some PG kiddos get dismissed for their very ability to blend in and not make waves with peers. To meet unstated and nuanced expectations just about perfectly, basically, means that you're viewed as "can't possibly be unusual in any way."
I keep telling DD that
someday that ability is going to matter even more than her raw IQ will. That is, the ability to put others at ease and effortlessly, graciously interact with them at whatever level they happen to be at is an incredible PG-level gift,
too. Even if it does lead some of them to interpret that as her not actually being intelligent.
Which is mostly a problem for her dad and I, I suppose. It makes us indignant
for her as often as it makes her doubt whether she's really all that different. It's not
quite dumbing-down, but when it becomes a self-fulfilling prophecy in the hands of another adult, then it is obviously a problem. They see what they expect to see, basically. She is also a great one for internalizing the judgments of other adults into her self-image. So we do worry about that.
She doesn't spend a
lot of time with same-age peers, so her frame of reference is somewhat limited. The general scenario is that she enjoys the novelty of kids her own age. For a while, that is. Then it gets old because they tend to like HER a lot more than she likes them in large doses.
