One thing that could be a problem is breaking old habits. It's not that you don't understand what the new responsibilities or plays are, but just the fact that you've been doing something a long time and you're kind of used to doing it, it's a habit, and that's not what's required in the other system and that means kind of undoing something before you can even start to do something new.
— Bill Belichick
BreakingHabitsNot