Unless someone is in an abusive or destructive relationship where the perception of love is distorted by a manipulative or dishonest spouse, the only person who can decide when it's time to "call it quits" is one or both spouses in that relationship.

"Are we ever sure we're making the right decisions regarding our marriage?"

My answer, "No. Not really and not even with Jedi mind tricks."  

Gone With The Wind is the iconic love story with notable forewarning to us girls, hopefully early enough in our love life, to be cautious but not timid. The story has war, love, jealousy, tragedy and hope.  Some famous quotes both from Scarlett and Rhett are what many of us know as the representation of each character.