A professional is a man who can do his best at a time when he doesn't particularly feel like it.

The remark defines “professional” not as a job title but as a habit of character: the capacity to deliver one’s highest standard even when motivation, comfort, or enthusiasm is absent. It contrasts professionalism with amateurism understood as dependence on inspiration or favorable circumstances. The emphasis is on self-command—showing up, meeting obligations, and maintaining quality despite fatigue, boredom, discouragement, or personal distraction. In creative, athletic, and civic domains alike, the line suggests that excellence is less a feeling than a practiced discipline, and that trustworthiness is earned by consistency when it is hardest to be consistent.

1) “A professional is someone who can do his best work when he doesn’t feel like it.”
2) “A professional is a man who can do his best work when he doesn’t particularly feel like it.”
3) “A professional is a person who can do his best at a time when he doesn’t feel like it.”