Would you run a marathon without any training?  No, of course not, that would be crazy.  Labor is a marathon.  It is one of the most physically and emotionally challenging workouts you will ever go through so why on earth would you go into it without any training?  This is why you need to take a birth class.  A birth class prepares you for what to expect, it prepares your partner, and even does some emergency preparation in the event something comes up that you are not expecting.  In labor things can move really quickly, if you aren’t familiar with different options or procedures you could be making hasty decisions.  If you are knowledgeable you will be able to make sound decisions because you came prepared.  Bottom line is taking a birth class and educating yourself increases the chances that you are going to get the birth experience you want.