I must again say that my post about the amazing kids was culled from the reception reading thread - IT WAS NOT ABOUT MY DCs!!!!
(Anyway, NotAnOtter, agree about the big fish, small pond.)
As the OP was about boasting, I cited some examples of unnecessary self-congratulation. I'm quite sure no-one ever bears any ill will to the children of boasters, be they genuinely talented or otherwise, but bragging parents are really just plain rude.
I do have a problem with smugness - if you feel you are truly blessed with a brilliant child, beautiful home, handsome dh or whatever, just feel thankful and keep a lid on it.