And boredom can become apathy, a total lack of interest. Apathy leads to depression. You see, once you know what your best velocity is, you can stay in the zone almost all the time. You don't want to burn yourself out. You want to find your cruising speed so you can stay there all day long.
Velocity is a combination of energy and drive, combining the physical and the mental.
Your natural range of physical energy is enhanced or limited by your nutrition, fitness, the amount of rest you get, the way you manage stress, and your attitude. You also have a natural degree of drive or self-motivation. Drive is affected by your self-esteem, the clarity of your purpose and goals, your awareness of possibilities, the appeal that your goals have to you, and your ability to effectively plan and follow that plan. You love to work toward goals, particularly challenging goals. You have high aspirations and hold yourself and others to high standards.