Bink and Roisin, I've had similar experiences in my family also. I've had a couple family members who have been straight A students and the top X% of a very respected Grammar School. Living in a very nice middle class area where it was good to be clever they had no problems, academic or socially.
Other members have had some odd spark but not always shone as children or at school but later have done very very well. One whilst not being gifted, is very talented but the kind that only matures as an adult.
One of my own children was often commented on as a young child and had lots of isn't he clever comments. However he's had problems raised with him at school and certainly not at the top of the class.
My own experiences are what prompted my reply, not to get at people or put them down. But maybe to suggest when everybody doesn't rush to say yes your young child is G&T then maybe it's down to caution rather than resentment. If it wasn't for my family background I would've been fully expecting my own child to be bored at school and looking for a more academic pre-school.
Some children shine early and will remain that way, some may shine early then whilst keeping their own talents fade into the background school wise. Some will seem slow but then surprise everybody. Which is behind my "list" comments.