Confidence is good, but overly confident will put you in a position of being open to reticule. The instructors will SOAK in the fact that you're this 7 year USA swimmer or what have you and turn it into your worst nightmare. My roommate went in to BE a PJ (Now Security Forces with me, ROFL), you cannot call yourself officially a PJ until you've received the proper training and the privilege to wear the beret. Not saying you WON'T make it but, talking to my roommate who has experience, but unfortunate fell victim to an injury which ultimately got his washed out, was telling me it's mentally stressful beyond anything you have ever or will ever experience in your life and its going to put you in a place you've never been before. Good luck to you, if not see you in Security Forces :\