can you be more specific about what exactly you're asking here?

are you asking "would an ordinary person encounter events in which game theory would be applicable on a normal, day-to-day basis?"

or are you asking "would an ordinary person who has studied game theory (but is not especially well versed or practiced) be capable of using it when it comes to making decisions?"

also can you please specify what you mean by an "ordinary person". how good are they at linear algebra and probability?