First let me tell you that my DD, 8 yrs old, still thinks the costume characters are real, she doesn't know yet that they are people dressed up. I know she may be a little old to believe this but I like that she is still so innocent and do everything I can to keep her from growing up to fast. I want her to enjoy being a child, to many kids grow up so fast these days, with that said....
We took our DD to WDW for the first time in 01/04 right after she turned 6. She would not go anywhere near the costumed characters like Mickey and Minnie only the Princesses and Peter Pan.
We took her back in 12/04 for her 7th birthday with the stipulation that she had to have her picture taken with Mickey and Minnie because she was to old to be afraid of them!
When we were walking away from her 1st visit with Mickey she said to me "that was weird, he didn't talk to anybody, I wonder why he didn't talk?" Then it was like a light bulb went off in her head and she said "I know why he didn't talk! If were to talk to people they would have so many questions for him he would never get to leave and he has alot to do around here!" I told her that must be the reason.
Luckily she's never questioned why the Princesses are able to talk with guests and still get their work done but the costumed characters can't. Oh well, sadly I think this March trip will be the last that she believes.