One way or the other.. this reality.. is teoritisk.. or a simulation..
Since einstein we knowed that time is relative.. and the atoms follow a different set of rules.. than the world we are showed..
And we now know that time, space, atoms and even light are relativ to the observer.. (and that can be proven, in numbers of experiments)
But i like to think that we (the human race) did it our self.. I call the teori "Selftrix" I consist of 5 very likly senarios of why.. (not ready yet)
But like man.bear-pic says.. we will never know in this life..
But even if it is the one and only teori that can explain everythin.. don't be afraid.. It dosent matter if we live in a "big", "flat" or simulated univers.. our kids are still made up of mother and father dna kode..there are no differents..the only differents is... that dead are mayby not the end.. and thats not that bad.
(sorry for my english.)