No, I don't think its too early. My DS was barely three when he started to make comments to me that showed that he recognized the difference between himself and his "classmates" at daycare. Trying to pretend like the difference isn't there won't help. These kids are too smart to expect them to not notice. We have worked hard to make sure that DS understands that it is effort not innate ability that gets rewarded here. We have also sought out experience for him where we knew he would be outside of his comfort zone and would probably not excel, at least immediately. It is just as important, if not more so, to me to teach my child the worth of all people (and not just himself) as it is to teach him any kind of academics. When a child repeatedly hears how "special" they are and how "brilliant" they are they do need to be reminded of the more important things in life (i.e. character, perseverance, humility, etc...) in order to keep them grounded. My DS knows that his brain is a gift from God and that it works differently than most people's brains do. He also knows that it is up to him to use that gift well. That doesn't mean to be perfect, it means to take chances in learning, to try to help others, to think about and do the right things, etc... We have also made sure to make him aware of the various gifts that he sees in people all around him.
A genius mind without a sense of himself within the larger world is not likely to provide him with a better life but a gifted mind attuned to the world around him can make a difference in many ways, large or small.