It's not whether the glass is half empty or half full, it's who is pouring the water. The key in business and success at any endeavor is doing your best to control your destiny. You can't always do it, but you have to take every opportunity you can to be as prepared as-and ahead of-the competition as you possibly can be.
Mark CubanLearn to sell. In business you’re always selling: to your prospects, investors and employees. To be the best salesperson put yourself in the shoes of the person to whom you’re selling. Don’t sell your product. Solve their problems.
Mark Cuban