Our training revolves around us reacting and making decisions when that's happening. It unlocks your brain to move faster than it is used to moving because the faster you move and do what you are ordered to do, the sooner the yelling and chaos stops. It is so we don't become frozen in combat situations and make the best decision at that moment. The hardest part was the first 2 weeks when we started, those 2 weeks were when everybody was getting smoked for mistakes or freezing. Some learn it the first day, 99% has learned it by the end of those 2 weeks. 1% is Pvt Pile, and every platoon has 1 or 2, typically not more than 5.