Just to expand on what Paulius said, here’s a more in-depth look at lucid living and the concept behind it. Linky
Many of those who do have lucid dreams every night, such as Wyvern, use this technique mainly. In the end, WILD, MILD, DILD, RCILD, VILD and the rest depend on awareness to at least some extent, and it can also make your day a bit more interesting when you pay attention to the world around you.