I have a theory that when you remember events you make time go backwards to the event itself.

Thats why a memory is never clear - because quantum mechanics precludes you remebering the exact event but rather you can actually recall information about the event which was not present to your conscious self at the time of the event. This means that this time travel backwards does not alter the present. eg when you travel backward in time to the event - you actually really do see the event again but from a slightly different perspective.

This time travel is an ability of mind rather than brain, so is very difficult to measure precisely but its affects can be felt.

It may be possible to travel back in time and reinvestigate an event.

Perhaps this is done in hypnosis.