We’ve all wished we could be someone else, whether it’s just polishing a few dull spots in our personality or fully rewriting the story of our lives, Jay Gatsby-style. If you're a procrastinator, you may have wished you could be more productive; if you're gloomy, you may have hoped you could be more optimistic; if you're shy, you may have longed to be the life of the party. Changing a core personality trait (such as introversion) is difficult. But what you can change is your behavior. It's never too late to do what you want to do, and with a little sweat and a little luck, you can break out of old patterns and be just who you want to be.