There is no substitute for attentive repetition.

Deep practice feels a bit like exploring a dark and unfamiliar room. You start slowly, you bump into furniture, stop, think, and start again. Slowly, and a little painfully, you explore the space over and over, attending to errors, extending your reach into the room a bit farther each time, building a mental map until you can move through it quickly and intuitively.

Skill is a cellular insulation that wraps neural circuits and that grows in response to certain signals.

There is no substitute for attentive repetition.

I discovered when I went all out, when I put 100 percent of my energy into some intense, impossible task - when my heart was jack-hammering, when lactic acid was sizzling through my muscles - that's when I felt good, normal, balanced.

The sweet spot: that productive, uncomfortable terrain located just beyond our current abilities, where our reach exceeds our grasp. Deep practice is not simply about struggling; it's about seeking a particular struggle, which involves a cycle of distinct actions.

You have to be willing to stop and fix. Deep practice requires a willingness to do what many of us find uncomfortable: to admit to our errors, and focus on them.