Unless of course We created the simulation. And you (among others) have voluntarily forgotten the fact, in order to better appreciate the full immersion experience.
As the case may be, taking into consideration that it would be consistent with in-between-life hypnoregression. http://newtoninstitute.org/
perfect copies are impossible ala conservation of quantum information http://arxiv.org/pdf/quant-ph/0306044v1.pdf