How can I pass up an opportunity to educate a child, you ask?
There are a couple of answers.
First, I'm not sure a street-corner spiel from me will really do much good, educationally. I believe that, in general, attitudes change after actions change. When people are forced to treat us as full citizens, they will start to think of us that way.
Talking is useful as an adjunct to action, but I quit giving "what it's like" talks several years ago because no matter how articulate I was, my audiences seemed to come away with the impression that I was an oddity, a museum exhibit, someone whose life was so different as to need explaining.
I now speak to many varied audiences, but never about myself. I discuss disability rights, various legal and political issues, the telethon, the "right" to die. I also appear publicly in support of organized labor and progressive political causes because I am a well-rounded citizen and not just a disability-object.
I think I've been most effective in changing attitudes when I've simply behaved like a "real person" instead of a "crip totem" -- when I've won a client's legal case, given directions to a lost tourist, accepted a candidate's filing for public office, or tipped well for good service in a restaurant.
Second, I think kids need to learn about manners and social boundaries, just as they need to learn about disability. Actually, learning not to ask me questions about my disability is part of learning about disability: they are learning to respect a disabled person's privacy and personal integrity.
When accosted with these questions, I do not act rude or uppity or offended (though perhaps I may rightly feel that way). I give 'em my best Dixie grin and say, "I am so sorry, but I do not discuss my medical condition with strangers. I am sure you can understand that," or "I am so sorry, but I am on my way to work and do not have time to give proper attention to a very complicated subject right now."
The kids may not be absorbing info about my specific disability, but they are learning that someone like me has things to do and places to go. In the end, I think that's an important lesson.
I used to have more energy for that kind of thing than I do now -- I've been conspicuously disabled since I grew out of a stroller into a wheelchair -- and I'm 41 years old. But when you're out educating, maybe it would be good to warn folks that if they keep asking personal questions of complete strangers, they will eventually run into someone who prefers not to answer them. They need to know it's no more appropriate to intrude on our space than it is to accost any other minority group member and demand one-on-one instruction.