Even if you have a natural ability if you are not constantly recreating yourself at the piano you will eventually hit a wall and get no where. You have to always question how you play a particular section, the depth and strength of your questioning will highlight your ability as a musician. Those who do not know how to ask questions about how to play a particular section really need the guidance of a teacher. So it is very hard to rely on your physical playing ability. I have met many people who have the physical ability to play, but the logic and mental aspect of memory and reading needs development. Everyone can play insane/hard music, but not everyone can think their way though it.
I still take lots of time sitting and repeating passages, drilling them until they are played without consious thought and i can just listen to the sound. I havent met anyone yet who can do that automatically, i have head many who can play from ear what they hear, but the real expression and passion is lacking. That soulful part of music has to be with long period of practicing struggle and strain, if it isnt I dont see where the expression and passion of your music gets it fuel from.