Everybody has one.
Whether we’re aware of it or not, we each live our lives according to our own personal internalized philosophical theory—a more or less contradictory jumble of assumptions, beliefs, intentions, and hypotheses about the nature of the universe and our place in it. Each of us has ideas about the nature of existence, motion, and relationships. They come from everywhere and blend together: experiences, conversations, reading, mass media, advertising, teachers, family, friends and foes. (And most importantly, cartoons).
We can think through these theories, try to break them down and understand them, experiment with putting them into practice to determine what is correct and incorrect. As we learn to apply theory, we are able to increasingly align our actions with our thoughts.
The other option is to passively accept the premises and outlook that we’ve been trained in since birth (which, since they are products of the system‘s ideological hegemony, lead to spontaneous total identification with the system), and meekly follow the path our enemy has laid down for us: school, work, unemployment line, prison, FEMA camp, nursing home, death.