Dreaming is an interesting topic indeed. I haven't had too much lucid dreams, heck I can't even remember them most of the time. But for all I know I haven't got any nightmares since I was a kid... As for ur perfectly unknown faces, the simplest thought is that it might not be that strange, since u can create entire landscapes in ur dreams without ever having seen them before... So u might be overthinking this one. Though that being said I do think it's very likely we live in a simulation ^.^ And if I were to start philosophizing about your dream I could come with some other "possible" meanings to it.