We each have sources of energy, both in terms of our biological and psychological processes. Those processes do not run correctly without a good source of energy. Without proper nutrients and vitamins (in addition to exercise and rest), our biological processes gradually degrade and we become lethargic, prone to sleeping and very little activity of significance. In much the same way, without positive input to our psyche and exercise and rest thereof, our mental processes gradually degrade and we become dull and given to random bursts of highly irrational behavior.
So if you find yourself acting strangely, review your diet, exercise, and sleeping patterns. Ask yourself what you are taking into your mind via music, social activities, and personal time. You may be running on gasoline when you could be running on jet fuel.