Pessimism and optimism are not just ways we predict the future; these attitudes profoundly affect the future. Pessimism makes our disposition dark and gloomy. Optimism is a source of light and energy for everyone in range of its power. Both are contagious. It’s true that some people are more naturally optimistic, cheerful, and hopeful than others but even people with a negative predisposition can train themselves to see the bright side and expel thoughts of doom and gloom. Making the decision to be positive can be the most important in your life.