You're sitting in front of the computer, reading through the Whyville Times, when all of a sudden, someone sticks their hand right in front of your face. What do you do?
You'd probably close your eyes, turn your head, and lean back. All of this without thinking about it. These, my fellow whyvillians, are your reflexes.
As a newborn, most of the things you did were probably just reflexes. After some time, the reflexes faded and you learned to do things voluntarily. Test for some of these reflexes the next time you see a baby - but make sure to ask for a parent's permission first!