All too often, we are our own worst enemies. While it’s good to be aware of mistakes you’ve made in the past and improvements you can make in the future, beating yourself up on a regular basis is a surefire way to wind up singing the blues. In fact, self-criticism can just make you more miserable. So instead of dwelling on your past failures, focus on how and why you value yourself. This shift will make you stronger, more productive, less stressed . . . and, yes, happier.