In the military this philosophy served me well....
If you don't know the rules/SOP, you're incompetent.
If you follow them rigidly, you're uninspired.
A flexible and inspired combat leader knows the rules as a baseline from which to deviate as needed to accomplish the goal (peacetime = safety, wartime = victory).
In civilian aviation our goal is safety, and the rules cannot (nor do they pretend) to address all possible situations. But you should follow them unless you have a good reason not to. That keeps you out of regulatory trouble, and also it's possible that there might be a good reason for a rule that you're not aware of.