Don't let the little downers of life interrupt the flow of your enthusiasm. If you expect to succeed in the world of sales, it's imperative to maintain a steady flow of optimism and energy. It won't do any good to let minor headaches sour your attitude. Customers can sense when you're preoccupied with your troubles. Guess what? They have problems, too. It's your job to help solve them. You're more likely to see solutions when your attitude is one of cheer.