[laughfactory]

I've actually thought a lot about exactly that: how can I be certain that anyone else actually exists? They could all, you could all, be NPCs populating my universe of one. The argument for this is that it takes far less computational power to render such an experience than it does to render that same experience for billions of people and all their complex interactions. But if it's one person than you simply render what they are currently experiencing. You don't render far off places, economies, environments, etc. Just focus on the individual.

And perhaps it's no simulation at all, but some super realistic form of VR (via brain implant?). Perhaps if the future world is a wasteland than this may be a way for future people to experience the "good old days." Or perhaps this is how education is conducted in the future: we live some number of virtual lives before getting a crack at a real one.