BACK STORY

Whether a novel, a film, or a stage play, the characters will have a back story so-called, which is their history prior to their appearance in that novel, film, or play.

But then we, too, have a back story, such as, for instance, who our parents were, where we went to school, how many friends we had and who they and their parents were, whether it was a positive environment we grew up in or whether it was negative.

But there is another back story and that is who we were in our previous incarnations.  The details of this are not available to us directly, of course, but they can be supposed accurately enough, based on how our current lives are going.  Vedanta and Buddhism teach that the karma that we carry from our past lives determines our present fortunes.

If we are now enjoying good luck and happy experiences, then who we used to be was a person who was kind, generous, and helpful to others.  If in our present life we have much misfortune, tragedy and suffering, then it is certain that in our past lives we were horrible toward everyone and everything.

Interpreting karma is a tricky business, though, because there are gray areas where it is not clear whether something is positive or negative.  What decides it is the intent, what the person doing the act meant by it.
 
If, for example, a person gives a gift to someone, but does so with hate in his heart, then the result is bad karma.  But it is good karma if a person saves someone from drowning, even though the one drowning is a crook.  Crooks can change their ways.
   
While we cannot know the details of our past lives, how our current lives are going tells us a great deal about the intentions of who we used to be.