Self-employed people tend to be happier because they're able to make their own decisions without being challenged. You can get the same benefits by being a supervisor in a corporate environment—by being able to work independently. Being in control of the speed at which you work—meeting your deadlines in your own way—is key. A supervisor dictating your every move stifles satisfaction. If you do have to agree to a timetable, better a colleague's than a boss's, and better a customer's than a colleague's.