When we are learning to drive, the skills mostly begin as external rule-based exercises that often feel very complicated and even awkward. But as our subconscious mind assimilates and coordinates more and more of the necessary movements, data, facts and limitations, then the skill is largely internalized and the conscious mind is freed up to think and dwell on more interesting things.
If some of those skills are learned incorrectly or maybe ignored in favor of some other stronger desires, like the craving for speed or the body-pressing sensation of acceleration and power, external forces may be employed to remind us of the parameters imposed on drivers. Or, if our subconscious mind is impaired by drugs or sleep-deprivation, we may find our natural ability to drive largely missing, endangering ourselves and those around us.
When I tried to drive home one time while under the strong influence of pain medications I found out the stark difference between driving naturally and driving with only the conscious part of the brain. It was terrifying as well as very exhausting.
So too is external obedience. It may look right and be technically correct according to code, but if it does not flow naturally from a heart fed and nourished by love it consumes most of our attention and energy and leaves us more and more exhausted and frustrated. In God's economy it is not really obedience, but just performance of self-promotion.
“Beware of making a fetish of consistency to your convictions instead of being devoted to God. 'I shall never do that' – in all probability you will have to, if you are a saint. There never was a more inconsistent Being on this earth than Our Lord, but He was never inconsistent to His Father. The one consistency of the saint is not to a principle, but to the Divine life. It is the Divine life which continually makes more and more discoveries about the Divine mind. It is easier to be a fanatic than a faithful soul, because there is something amazingly humbling, particularly to our religious conceit, in being loyal to God.” (My Utmost for His Highest 11-14)