Intelligence is an interesting trait because it can so easily lead to egotism and related problems. Parents post here about such things all the time.
I wouldn't suggest hiding it from one's self, but I also don't think it's the best idea to openly put one's giftedness out there in all settings, no. There is a big likelihood that non-gifted people will think that you are saying you are better than them (and you are, in one way), and react negatively. And it's hard to say that such reactions are wrong; when one person chooses to talk about the extent of their intelligence, they often are bragging, whether well-founded or not. There is also a chance of attracting the attention of aggressive people who want to prove themselves against you in one way or another; I sometimes take pleasure in competition with those people, but don't need constant confrontation to feel good about myself either.
I simply think it's easiest and best to let one's actions speak for themselves, most of the time. I also don't think that giftedness is an aspect of cultural identity in the same way as membership in an ethnic group, for instance. My idea is not so much about hiding one's self, as about not actively promoting an aspect in a way that's bound to cause friction.
