Pitch black again. Like someone extinguished an angel. - Steven Kotler

brainwaves slow from agitated beta to daydreamy alpha and deeper theta. Neurochemically, stress chemicals like norepinephrine and cortisol are replaced by performance-enhancing, pleasure-producing compounds such as dopamine, endorphins, anandamide, serotonin, and oxytocin.

mindset impacts emotion, which alters biology, which increases performance. Thus, it seemed, by tinkering with mindset — using everything from physical to psychological to pharmacological interventions — one could significantly enhance performance.

As children we are taught not to play with fire, not how to play with fire.