People are probably not being as dismissive as you think. Your son probably looks like a 4 yo and moves like a 4 yo and therefore he gets treated like a 4 year old. It is impossible for people to know that your child is gifted. The questions you say they ask are appropriate. I could see myself asking those questions to a 4 year old.
I'm not that forgiving! I think too many people talk to children as if they're idiots, whether gifted or not. I tend to talk to kids at a high level, and only then if I see they don't understand me (vacant stare), I'll lower my level. I'm sure this is partly due to my experience of knowing that my infant understood me much of the time, but I never used baby talk before kid either. (Of course, i'm sure i'm part of the problem of creating too much of a child-centered community.)
Edited to say: mamabear, i'm not implying that you talk to children like they're idiots! I know you don't.
