I think this one of the main reasons many gifted (may be HG) kids fail to reach full potential.
From my personal experience I think I am not PG, but may be MG. I was never tested, skipped a grade and consistently the first in the class. I always used to beat my collegues, who are smarter than me by just hard work and keeping my foot on theground. I am a surgeon in one of highly specialized branch and all that acheived by hard work and some use of my gifted intelligence.
I put this in this forum to see any of you had similar experiences and how you dealt with it