Short idea (27): Some psychologists such as James and Jung have distinguished between Active Thinking and Passive Thinking. Active Thinking is work, because it requires an expenditure of energy over time. And, like any work, it can exhaust.

Short idea (119): We all feel filled with Energy sometimes, bursting with Energy; at other times listless and sluggish and filled with inertia. This feeling of Energy has a psychological label: Libido (sometimes "Libido" is used to refer to all psychological energy, sometimes only to sexual energy). If we look at objects in the physical world we can often see what fills them with energy. For example, a moving object hits one that is still, and the second objects moves, filled with the energy transferred from the first object. It is not so easy to see what fills us with the feeling of Energy or takes away the feeling. If we do see what does, it is difficult to understand how this can happen. For example, how can bad news make us feel all the Energy draining from us? We may be able to picture how a virus could take the wind out of our sails, but how can hearing bad news do it?

Short idea (178): The only way not to have expenses and expenditures is to be dead.

Short idea (194): Mania and Anxiety can be seen as forms of increased psychological Energy (Libido), that is, excitement. Each can be taken as the opposite of Relaxation.