This is an extension of my piece on relationships.  Basically, I argue that relationships become uninteresting and fail when one party takes another party for granted.  The partner being taken for granted is viewed as expendable or lame, and they end up feeling devalued no matter how much more they put in the relationship to make it work.  Being taken for granted can lead to resentment and indignation, and it can be seen as an affront to the relationship at large.  

Once there is a shift in a relationship and both parties stop taking each other for granted, they are able to appreciate, respect, and value the other person.  They look forward to their significant other while realizing they have to work towards keeping them in their lives.  The clip below got the lesson wrong, i.e. "By acting it, you will become it."  But this clip highlights another lesson, i.e., taking your significant other for granted leads to failed relationships but if you realize they are very much time bound in your life, you start appreciating them more.