Answer: Tiredness comes from a lack of importance of the goal. This is due to the fact that you are not receiving enough positive stimulus from the group. If you were, then you would light up.
It is the group’s duty to elevate each of its members. Since the group includes everyone, you must all work together on the common desire and aspiration. Then, everyone will have the strength to advance. It is called mutual guarantee when we all connect in order to give each other the strength to attain the goal of creation.
From the Fundamentals Kabbalah Lesson 10/30/11