How long ago is 'A long time ago...?'

     'Far, far away....' is a given.

     For me, a long time ago would be 100 B.C., or 10,000 B.C.

     So, when did the events in Episodes 1-6 happen in correlation to us?  Or is it all false, and it is all actually in the future? 

     So, humans that look just like us developed in another galaxy?  Or do we migrate to another galaxy?