I've noticed that my moments of realization that I am dreaming are seldom enough to propel me into lucidity. Typically, to gain any kind of control over my dreams at all, I have to say "this is a dream." The weird thing is, I'm usually able to say "this is a dr-" and then my jaw goes stiff, and I can't force any sound out. After maybe 3 or 4 tries, I'll manage to finally stammer it out, but then I have a whole new set of issues to deal with.
For one, it's really hard for me to retain control over my dreams. Immediately when I become lucid, things will start happening beyond my control. I can typically exert masterful control over one thing. I can teleport once or fly once or create something once. And after that, it's nearly impossible to replicate the feat. It's nearly impossible to do another feat at all: the longer I fly, the harder it becomes to remain aloft; the more I try to control something, the harder it becomes to continue manipulating it; etc.
I also am continually victim to false awakenings. Typically after going lucid I will immediately dream that the shock woke me up, but it will in fact be merely another layer of the dream. It's starting to get really frustrating, because I have no problem going lucid. It's doing things while lucid that give me the slip.