“Deep concentration causes the energy consumption in your brain to go up by only about 1 percent. No matter what you are doing with your conscious mind, it is your unconscious that dominates your mental activity – and therefore uses up most of the energy consumed by the brain. Regardless of whether your conscious mind is idle or engaged, your unconscious mind is hard at work doing the mental equivalent of push-ups, squats, and wind sprints. O.”

“Deep concentration causes the energy consumption in your brain to go up by only about 1 percent. No matter what you are doing with your conscious mind, it is your unconscious that dominates your mental activity – and therefore uses up most of the energy consumed by the brain. Regardless of whether your conscious mind is idle or engaged, your unconscious mind is hard at work doing the mental equivalent of push-ups, squats, and wind sprints. O.”

— Leonard Mlodinow