Imagine your self as a tree. You require soil, water, and sun.
How does water ascend from the soil all the way up to the tips of your leaves?
A small portion of the energy may come from your roots.
The pathways inside of you are mainly conduits for the water to rise, and cannot really pump the water upwards.
Most of the energy comes from the sun, from energy that causes evaporation in our leaves. This creates suction. This energy is so powerful that it can draw water up to the top of a 100 metre redwood tree.
I see this as an analogy to energy and motivation in our lives. We can't provide all of our own energy and motivation. We must be involved in external things which draw action out of us, as the sun and its evaporative effects draw water all the way up a very tall tree. This leads to continuous "columns" of action, beginning at the roots, ascending to the outer portions of our selves. Others (other relationships, other involvements in community) are necessary to keep this cycle going. It is very hard to generate your own motivation all alone--"root pressure alone" can only go so far.
Many of my patients with low motivation and energy try very hard to initiate activity. A turning point can often be when they become involved with others, or with a community, or with some other external structure, that can help keep this "column" of motivation rising to new heights.