Thomas, don't go.  You're still my best friend.
Commentary by Tony McRae

Guy meets girl.  
     Guy loves girl.  
          Girl likes guy.  
                                Girl and guy like being together.  
                                     Guy wants girl to love him.  
                                           Girl says goodbye.

Except for that last "goodbye" line, this sounds like an old pre-WW2 happy-ending movie.  You know, those wonderful screwball comedies of the 30s and 40s where Cary Grant and Katharine Hepburn or Barbara Stanwyck and Henry Fonda sideslip romantic love in favor of wisecracks and wackiness that gets them somehow back together.  This is what I was expecting from  Marc Webb's "(500) Days of Summer."

Not so.

First there's the "five hundred days" structure:  the film is divided into Days, but not chronologically, jumping forward and backwoods, keeping us on our toes.  For example, Day #10 is followed by Day #255 followed by Day #74, and so on.  On Day #1 Tom Hansen (played by Joseph Gorden-Levitt) meets Summer Finn (played by the effervescent Zooey Deschanel),.  He's hooked.  Even when Summer tells him she does not want more than a relationship built on pleasure and friendship, he still expects her to come around.  After having seen so many films of this type, we too presume Summer will see the light and succumb to Tom's persistence.  After all, happy endings are de rigeur in this type movie.

The movie's structure forces us to reorganize the storyline into a meaningful whole, which is a sly move on director Webb's part, for it gets us involved in the lives of both characters.  Since the story is told from Thomas's perspective, we tend to root for him in his efforts to convince Summer that he's her man.  Zooey Deschanel's Summer is a complex woman whose resistance is matched by Thomas's persistence.  

At one point, Summer appears to be caving in.  Thomas is walking on air, so much so that as he strolls  through the park, his euphoria becomes so contagious that  people begin following him.  There's even a band that celebrates his happiness.  It's a hilarious and heartwarming moment, a cinematic trope of a young man in love.  

The film's structure also has another intent: while we identify with Thomas and his love for Summer, the skipping between past and present gives us pause.  Perhaps Summer is not so fickle; she may have good reason not to commit to a permanent relationship, at least one with Thomas.  Zooey Deschanel is perfect as the illusive Summer.  Her eyes can convey what Shakespeare called "wondrous strange," and Marc Webb uses both editing and color to bring this out. 

As I watched Zooey Deschanel's character exude liveliness and sexuality, I was reminded of two Woody Allen women, Annie Hall in "Annie Hall" and Tracy in "Manhattan."  Diane Keaton's Annie is both screwbally and serious.  Mariel Hemingway's Tracy is unaffected and not as innocent as we might think.  Both are on their way to self-discovery.  Woody winds up with neither.    

Thomas and Summer are also in the process of self-discovery, which implies a happy ending of sorts, though not with one another.

This is romantic (adult) comedy at its best.