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 CarnegieIf you want to be happy, set yourself a goal that commands your thoughts, liberates your energy and inspires your hopes. Happiness is within you. It comes from doing some certain thing into which you can put all your thought and energy. If you want to be happy, get enthusiastic about something.
Dale CarnegieIf you want to know how to make people shun you and laugh at you behind your back and even despise you, here is the recipe: Never listen to anyone for long. Talk incessantly about yourself. If you have an idea while the other person is talking, don't wait for him or her to finish: bust right in and interrupt in the middle of a sentence.
Dale Carnegie