A typical sleep cycle has five stages and takes 90-110 minutes. During Stage 1 of your sleep cycle, you sleep lightly. At Stage 2, your sleep gets progressively deeper. At Stages 3 and 4, also known as "Delta Sleep," you sleep most heavily; this is when your body rebuilds itself.

Stage 5 of sleep, also known as REM (rapid eye movement) sleep, is marked by extensive physiological changes, such as accelerated respiration, increased brain activity, rapid eye movement, and muscle relaxation. People dream during REM sleep.Here's how it looks based on user reviews:

• You have a dream, as the last stage of your sleep cycle
• You realize that you are dreaming because it became odd or comes to the logical end
• To change the dream you decide to roll over

If nothing happens, then people completely forget about this and fall into a deep sleep shortly. But, here begins the magic!