Situations that do not demand constant task-focus—particularly boring or routine ones—free the mind to wander. As the mind drifts off and the default network activates more strongly, our neural circuits for task-focus go quiet—another variety of neural decoupling akin to that between the senses and daydreaming. Since daydreaming competes for neural energy with task-focus and sensory perception, there’s small wonder that as we daydream we make more errors in anything that requires us to pay focused attention.
— Focus: The Hidden Driver of Excellence (Daniel Goleman), Loc. 729–33