To put force, ability, or anything of the nature of an active faculty; to put in vigorous action; to bring into active operation; as, to exert the strength of the body, limbs, faculties, or imagination; to exert the mind or the voice.
To put forth, as the result or exercise of effort; to bring to bear; to do or perform.
There's a tremendous difference between alone and lonely. You could be lonely in a group of people. I like being alone. I like eating by myself. I go home at night and just watch a movie or hang out with my dog. I have to exert myself and really say, oh God, I've got to see my friends 'cause I'm too content being by myself. Drew Barrymore
The leader can never close the gap between himself and the group. If he does, he is no longer what he must be. He must walk a tightrope between the consent he must win and the control he must exert. Vince Lombardi
An engaged woman is always more agreeable than a disengaged. She is satisfied with herself. Her cares are over, and she feels that she may exert all her powers of pleasing without suspicion. All is safe with a lady engaged; no harm can be done. Jane Austen