The fact that some quantity is knowable doesn't necessarily mean that it needs to be known. I've quoted Bob Dylan many times here over the years: You don't need a weatherman to know which way the wind blows. Of course this isn't true in all cases. There are several different skills needed in order to be able to make judgement calls like this, and one of them is understanding the system/process well enough to know where the line is between prudence and overkill. If we constantly allow the tail to wag the dog, there will be much wasted time and effort. Another one I've used here many times came from Peter Drucker: There is nothing so useless as doing efficiently that which shouldn't be done at all.
