Why do we get goosebumps? Why do men fall asleep after sex? Do we really shrink as we age? Dr. Oz demystifies the body’s mysterious processes and reactions. If you’ve ever wondered why, now you can find out. Click here to quiz yourself on more of your body's medical mysteries.

Click here to watch Part 2. 

Whether it's falling or flying, Dr. Oz has the answers to why you have the dreams that you do and what they might mean.