I have a theory about this "lovely"
idea: I think that it came about because when kids have been pushed to memorize things at a young age, by parents thinking it will "give them the edge", the children seem highly intelligent until about 3rd grade, when they suddenly reach material where the "front loading" done by over zealous parents reaches its limit. At this point kids who had previously been thought to be super bright do seem to "level out" with their age peers. The problem is, that there are many more of these types of kids than kids like ours, so when a teacher runs into a truly gifted kid they don't recognize it for what it is - a truly smart kid.
I have no proof of this, but, based on what I have experienced with DD7 and other parents trying to find out "our trick" to teaching her all that she knows already
and having been a teacher in many K-12 schools, I think it has some validity to it.
