John is your average high school student.  He receives decent grades, spends time with his friends and is eager to go to college.  He arrives at college, excited about the freedom and the ability to do whatever he wants, whenever he wants.  He parties hard, has lots of fun, but manages to get straight D's his first term.  Depending on the school he goes to, that's about $4000-$40,000 worth of partying.  

Many students see going away to school as a chance to get away from their parents.  They are unsure about what it is they want to study, and the allure of non-stop partying and free booze becomes a focal point.  Or maybe they have never had to take care of themselves, pay their bills, or show up to a class where the teacher does not take attendance.

Whatever the reason, sometimes we all need time to grow up and learn about ourselves.  For many people, this is easily done while in school.  For others, a completely new environment may help them learn and grow.  Stepping out can give you that time to focus on yourself, decide what it is you want to do, or make your mistakes when you (or your parents) are not paying for school in the process.  

It is okay if this is a reason you want to take time off.  Probably all of us need time to grow up.  You have already reached a certain level of maturity if you realize this, or you realize that you want a break before reentering a structured learning environment.