The cynical side of me says, that in most cases it's probably best to keep your dreams to yourself. Most people don't care about what happens to you, they care about what happens to them.
Case in point, my fiance asked me over Christmas after we got engaged, "So, did you tell [names] about our engagement?" I said, "No, I'm not sure they would care. I told the people on my side and on your side that I know for a fact would."
But, the wise person in me says, there's nothing wrong with sharing your dreams with others. You don't don't have to change or diminish yourself to make other people comfortable with you.
BY SHARING YOUR LIGHT, YOU MIGHT CONSEQUENTLY BRIGHTEN THEIRS!