(500) Days of Summer is a story of boy meets girl, but it is not a love story. We know this because a basso profundo narrator (Richard McGonagle) tells us so in the opening moments of the film. The boy, Tom (Joseph Gordon-Levitt), ought to know this, too, because the girl, Summer (Zooey Deschanel), has informed him that she is not interested in having a boyfriend, that she wants to avoid anything "serious," and that she considers love an illusion. But Tom does not believe Summer, and to a considerable degree neither do we. Is this because we've been conditioned by the romantic tropes of Hollywood? Because love is so much more pleasant to presume than its absence? Because Ms. Deschanel is so unfathomably adorable? Perhaps a bit of each.
Alas, the story begins as the relationship ends, on Day 290 of the titular 500. Over the saddest pancakes I can recall seeing captured on film, Tom and Summer bicker (Her: "All we do is argue"; Him: "That is bullshit") before she offers a variation on the five cruelest words in the English language, "You're still my best friend."
From this sad hinge, the movie swivels forward and back, telling two stories in alternation: Tom's diligent attempt to construct a love affair with Summer, and his forlorn efforts to disentangle himself from the debris of its collapse. We leap from Day 28 to Day 303 to Day 167 to Day 408, oscillating between early hope and ultimate despair, the sudden, unbidden revelation of love and the slow, crushing realization that it is not requited.