why we can remember the pass but we can not go back?

1. again this is an issues of Time and Space.
2. the "space" is refer to the environment at the specific Time, for example : last night 9pm we were at cinema.
3. we just can not go back to the same "space" because we can not turn back the Time.
4. we are now at the current Time and Space or so called "This Moment", and those in our "mind" are those we can remembered.
5. agains, there is a limit of how much we can remember, beyound that it will be new to us even if we are actually "repeating" in a cycle....
6. so the unit of time is now used to represent how long we actually can remembered...
7. one thing for certain, we just cannot remember anything before we were born....
8. some say, any new life born is actually a result of transform of energy, not memory.
9. but maybe those lost memory is now in our DNA or Genetic which are no more in form of Memory...