Why do people sleepwalk? Scientists have studied this simple question for decades but have not yet found an exact answer for it. They have some good theories and possibilities. Most people think that when someone is sleepwalking that they are acting out their dream, but scientists have proven this to be wrong. Most scientists believe that you sleepwalk in your deepest stage of sleep when the brain waves are slow. During the day our brain is very active, but when you go to sleep your brain is very slow. On the other hand your body however is still active, it has really winded down your brain has. You have a body that is still functioning compared to a sleepy brain. Scientists have still not yet discovered the truth to this mind-blowing mystery, but this is their explanation of what most likely makes people sleepwalk.