Charlie Munger once said: “We have a passion for keeping things simple.”
Einstein says, “I soon learned to scent out what was able to lead to fundamentals and to turn aside from everything else, from the multitude of things that clutter up the mind.” Most of us try to consume more information, thinking it will lead to more signal, without thinking about how we filter and how we process the information coming in.
Knowing some basic principles helps as does knowing how to combine them. As Einstein says “A theory is the more impressive the greater the simplicity of its premises, the more different kinds of things it relates, and the more extended its area of applicability.”
It wasn't because he understood more about the complicated than other people, as John Wheeler points out in his short biographical memoir on Einstein:
Many a man in the street thinks of Einstein as a man who could only make headway in his work by dint of pages of complicated mathematics; the truth is the direct opposite. As Hilbert put it, “Every boy in the streets of our mathematical Gottingen understands more about four-dimensional geometry than Einstein. Yet, despite that, Einstein did the work and not the mathematicians.” Time and again, in the photoelectric effect, in relativity, in gravitation, the amateur grasped the simple point that had eluded the expert.
Where did Einstein acquire this ability to sift the essential from the non-essential? For this we turn to his first job.
In the view of many, the position of clerk of the Swiss patent office was no proper job at all, but it was the best job available to anyone with (Einstein's) unpromising university record. He served in the Bern office for seven years, from June 23, 1902 to July 6, 1909. Every morning he faced his quote of patent applications. Those were the days when a patent application had to be accompanied by a working model. Over and above the applications and the models was the boss, a kind man, a strict man, a wise man. He gave strict instructions: explain very briefly, if possible in a single sentence, why the device will work or why it won't; why the application should be granted or why it should be denied.
Day after day Einstein had to distill the central lesson out of objects of the greatest variety that man has power to invent. Who knows a more marvelous way to acquire a sense of what physics is and how it works? It is no wonder that Einstein always delighted in the machinery of the physical world—from the action of a compass needle to the meandering of a river, and from the perversities of a gyroscope to the drive of Flettner's rotor ship.
Who else but a patent clerk could have discovered the theory of relativity? “Who else,” Wheeler writes, “could have distilled this simple central point from all the clutter of electromagnetism than someone whose job it was over and over to extract simplicity out of complexity.”
Charles Munger speaks to the importance of sifting folly.
Part of that (possessing uncommon sense), I think, is being able to tune out folly, as distinguished from recognizing wisdom. You've got whole categories of things you just bat away so your brain isn't cluttered with them. That way, you're better able to pick up a few sensible things to do.