The firing of the circuit is paramount. Myelin is not built to respond to fond wishes or vague ideas or information that washes over us like a warm bath. The mechanism is built to respond to actions: the literal electrical impulses traveling down nerve fibers. It responds to urgent repetition. In a few chapters we'll discuss the likely evolutionary reasons, but for now we'll simply note that deep practice is assisted by the attainment of a primal state, one where we are attentive, hungry, and focused, even desperate.

