To make a fighter, you gotta strip them down to bare wood. Rest when you're dead. Come here. You can't just tell them to forget everything you know... you gotta make them forget it in their bones. Make them so tired they only listen to you. Only hear your voice, only do what you say, and nothing else.
All fighters are pigheaded some way or other. Some part of them always thinks they know better than you about something. Can you spare a few minutes for the Immaculate Conception? Truth is, even if they're wrong... even if that one thing is gonna be the ruin of them... if you can beat that last bit out of them, then they ain't fighters at all.