Lucid dreaming is a phenomenon where you are aware that you're dreaming, and it is unknown whether you are conscious or fully asleep during it. While having a lucid dream, some people report that they can control their dreams and what occurs during them. A good example of lucid dreaming can be found in the movie "Inception".
The possibilities of lucid dreaming are thought to be limitless. Researchers believe that anything you can conceive of during a lucid dream can come true, from flying over cities like Superman to re-living your oldest childhood memories. Most of us will experience at least one lucid dream in our lifetime, and one-fifth of Americans say they lucid dream on a monthly basis.
Personally, I have experienced a few lucid dreams, mainly in the last couple years. For those who have never had this experience, it is a feeling that cant really be compared to anything. It feels surreal during the dream, and when you wake up you aren't quite sure what just happened. That was my experience, at least.