You have to be mentally prepared for what you are about to get yourself into.
They purposely break you down and build you back up, both mentally and physically.
They do this on purpose. You are learning to go from thinking about yourself, to learning how to work with and as a team.
You will be phased to your limits and only you can push past them.
My 8 week course will give you the preparation you need.
What are you most worried about as far as preparation?