I don't think people should "know" about lucid dreaming (this topic is about getting the word on lucid dreaming out isn't it?). People who would want to ACTUALLY practice lucid dreaming eventually learn about it. Most people just ignore you if you tell them about it. And when someone does find out about it, they will eventually choose to try it or not so it all works out. And I also think that if a lot of people knew about it and practiced lucid dreaming than the skill wouldn't feel as valuable.