Yes Mike, I believe you are looking at time correctly. I believe that only "now" exists, but "now" is the sum of pervious changes. The only way to go back in time would be to reverse the changes leading to "now" in an exact order to arrive at some future point of change that is exactly like a previous state.

It may be possible to change to a previous state without following the exact sequence of changes that lead to the "now" state, a kind of accelerated change leading to a previous state..

Regards,

LelandJ