Darkness a symbolism of over consciousness, alertness & winning the heart beats & phobia of brain. Walking in dark is a step by step process. Do and die situation at each point. and full attention to the immediate present is the key..
But in the light we often mislead. We under grade it and instead of putting the best in the present, wastage of time in the uncertain future did pre occupy the mind.
Exams are just like that.
But one cant be Superman whole day thats why light & dark are the part of the day.