The fox knows many things, but the hedgehog knows one big thing.

In his book "From Good to Great", Jim Collins recounts a tale originally told by Archilochus the 7th Century BC poet.
Each day the fox aims to catch the hedgehog but is defeated. Whilst the fox is adept and possesses many skills it cannot win. Why? because the hedgehog rolls up to protect itself and the fox is jabbed by the spines.

In his famous essay “The Hedgehog and the Fox,” the philosopher Isaiah Berlin divided the world into hedgehogs and foxes, based upon the ancient Greek parable.
Hedgehogs' lives are the embodiment of a single, central vision of reality according to which they "feel", breathe, experience and think - in short, "system addicts".
Foxes live centrifugal lives, pursuing many divergent ends and, generally, possess a sense of reality that prevents them from formulating a definite grand system of "everything".