You act to get what you want

What we ultimately want is to be in a particular mental state, and the only way you get to be in that particular mental state is through taking action. Taking action involves:

Getting what you want involves a single action or a series of actions. If our want is simple, a single action can fulfill it. If our want is complex, multiple actions need to be performed in order to fulfill it (i.e, project). A life purpose is a complex want. Getting to it will involve multiple actions. In fact, life is a project.