We all sleep, but have you ever wondered why we do, and how we actually fall asleep? Look deeper and uncover some of the mechanisms and science behind what our bodies go through when we fall asleep, and how we are still learning exactly what parts of our brain dictate how and when we sleep. Plus, does caffeine affect sleep patterns? Don't think too hard about this, or you might lie awake at night, surfing the TV, trying to figure out how to fall back asleep.