I seem to encounter the jealous and bitter ones LOL. Or the really proud, amazed ones. In my eldest's class, there is a mum whose baby is six weeks older than my 11 month old. When we go in, my baby sometimes walks in. When she sees this, she gets her baby out of the pram and tries to get her to walk; when she starts crawling, the mum's look of frustration says it all. Of course, that's only walking- hardly an indicator of brilliance- but is representative of their reaction to my eldest's achievement.
I also have a "friend" who is extremely competitive and is constantly making up lies about her daughter's abilities. I feel that she wouldn't lie about it unless she is trying to cover up the disappointment in her daughter; because her daughter doesn't lie about it, just the mum.
I just find it hard to accept that parents can feel this way about their kids, and also about others', instead of feeling happy that a child may have an easier life in this horrible world. I am grateful that gifted children exist. How sad that anyone could think badly of any child.
