Hmm, this is a tough one, I can't say I've ever had this problem, but I have heard a lot of people with it. From what I understand, even though you're not over exited, you're more anticipating what you can do.

What I suggest is randomly, throughout the day, suddenly come to the conclusion that you are dreaming, really live all of the emotions that come with it, then to a reality check, just to make sure. Unless it really is a dream, the sky won't go read etc, but by doing this, it gets you're mind used to entering lucidity and not waking up. Eventually this will work in youre dreams

~Alex