Surprisingly most of the time and energy spent in training to become a professional pilot is spent on the ground. All professional pilots understand that greater knowledge and understanding is what develops the best pilots. As a general rule of thumb, for every hour you spend in the airplane plan to spend 10 hours studying on the ground. Assuming your program is around 280 hours of flight time, that means you will spend around 2,800 hours studying on the ground. Your average day will have a mission with your instructor, but then it's up to you to follow your study regimen to ensure that you are ready for the next training activity.