The only way to get good at fighting is to fight. But that is never a realistic proposition. Too much fighting destroys the fighter before he can get good. This is why all martial arts (including boxing) has shadow boxing routines. The fighter there fights against an imaginary opponent. That opponent is perfect, relentless, tireless. The only way for the fighter to beat that opponent is for himself to become perfect, relentless, tireless. Yet fighters are made of flesh and bone. We make mistakes, we hesitate, we get tired. So it’s true. The first enemy the fighter has to beat is the only enemy he ever has to beat: himself.