To be too conscious is an illness - a real thoroughgoing illness. ~Fyodor Dostoevski
Attentive awareness with intense totality and total intensity is required for everyone to make the optimum utilization of the consciousness; if consciousness were unnecessary then the Divine energy which occupies the human specious would be without it. Having said all these, anything in excess is bad. Everything needs intervals and rest or else that would be handled by an ending either sudden or gradual as is the case with the functioning of our brain and heart resulting in the death of this body.