1. Every human movement, thought, or feeling is a precisely timed electric signal traveling through a chain of neurons—a circuit of nerve fiber.
2. Myelin is the insulation that wraps these nerve fibers and increases signal strength, speed, and accuracy.
3. The more we fire a particular circuit, the more myelin optimizes that circuit, and the stronger, faster, and more fluent our movements and thoughts become.

Because the best way to build a good circuit is to fire it, attend to mistakes, then fire it again, over and over. Struggle is not an option: it's a biological requirement : in order to get your skill circuit to fire optimally, you must by definition fire the circuit suboptimally; you must make mistakes and pay.

• Because wrapping myelin around a big circuit requires immense energy and time. If you don't love it, you'll never work hard enough to be great.
• The more we develop a skill circuit, the less we're aware that we're using it. We're built to make skills automatic, to stash them in our unconscious mind .

Myelin wraps it doesn't unwrap. Like a highway-—paving machine, myelination happens in one direction. Once a skill circuit is insulated, you can't uninsulate it (except through age or disease). That's why habits are hard to break. The only way to change them is to build new habits by repeating new behaviors—by myelinating new circuits.

Every expert in every field is the result of around ten thousand hours of committed practice. Ericsson called this process "deliberate practice" and defined it as working on technique, seeking constant critical feedback, and focusing ruthlessly on shoring up weaknesses.

• ABSORB THE WHOLE THING. This means spending time staring at or listening to the desired skill.
• It sounds rather Zen, but it basically amounts to absorbing a picture of the skill until you can imagine yourself doing it.

• There is, biologically speaking, no substitute for attentive repetition.
• Myelin is living tissue. Like everything else in the body, it's in a constant cycle of breakdown and repair. That's why daily practice matters, particularly as we get older.

Deep practice is not simply about struggling; it's about seeking out a particular struggle, which involves a cycle of distinct actions.

1. Pick a target.

2. Reach for it.

3. Evaluate the gap between the target and the reach.

4. Return to step one.

• Going slow allows you to attend more closely to errors, creating a higher degree of precision with each firing—and when it comes to growing myelin, precision is everything.
• "I am slow to learn and slow to forget what I have learned," Lincoln wrote. "My mind is like a piece of steel, very hard to scratch anything on it and almost impossible after you get it there to rub it out."

• Ignition: The moments that lead us to say that is who you want to be. We usually think of passion as an inner quality. But it is something that came first from the outside world.
• Future belonging is a primal cue.
• It's not as simple as saying I want X. It's rather saying: I want X later, so I better do Y like crazy right now.

Brains are always looking for a cue as to where to spend energy now. Now? Now? We're swimming in an ocean of cues, constantly responding to them, but like fish in water, we just don't see it."