turn back time

It’s not.
Just because I don’t know exactly how to do it yet, it doesn’t mean that I will never do it – or, indeed, that YOU can’t do it. (Just don’t forget to come back, please, and help ME out, OK? ;))

Nothing is impossible: maybe for man (I doubt it), but certainly not for God or whatever you call your Supreme Being, the Master of Times.

Besides… How would you or I even know if we DID it? ;-)