Enthusiasm is that ingredient of vitality mixed with a firm belief in what you are doing that ensures the success of any project you undertake.
Dale CarnegiePsychiatrists declare that most of our fatigue derives from our mental and emotional attitudes... What kinds of emotional factors tire the sedentary (or sitting) worker? Joy? Contentment? No! Never! Boredom, resentment, a feeling of not being appreciated, a feeling of futility, hurry, anxiety, worry-those are the emotional factors that exhaust the sitting worker, make him susceptible to colds, reduce his output, and send him home with a nervous headache. Yes, we get tired because our emotions produce nervous tensions in the body.
Dale CarnegieIf you got it, ask yourself why and try to repeat the action. If you failed, ask yourself why and try to learn from the experience.
Dale Carnegie