The main reason for fatigue at the end of a day is the loss of spiritual energy through waste thoughts or extroversion. Although I may not expend a lot of physical energy in the day, I can know that if I am exhausted at the end of the day it is because I have allowed the spiritual energy to be drained by focusing too much of my attention outside of myself. Today, instead of speaking too much and wasting my energy, let me conserve my energy through a positive focus inwards.