You know you’re going to like it even before the first scene plays out. You know it’s going to be slightly irreverent, witty and different.

Different in a good way. Original and (rare for this genre) unpredictable. I’m not sure the last time I saw a radically dif ferent romantic comedy. Not of the really good kind. Fortunately, “(500) Days of Sum mer” is the really good kind. One of the best films I’ve seen this year.

Maybe that’s because “Summer” isn’t technically a romcom. It’s more of a relationship film, an offbeat romantic quest for love, not simply the bumbling premonitions of love that most flicks try to depict.

Tom (Joseph Gordon-Levitt) writes greeting cards. He’s really an architect, but one senses that Tom’s afraid to leave his comfort zone. He’s good enough at writing greeting cards to trap himself in a dead-end, feel-good job.

Summer (Zooey Deschanel) is his boss’s new assistant. They meet and flirt. Tom, a firm believer in love, is immediately smitten. Summer believes love is an unobtainable myth. They agree to disagree and begin dating . . . casually dating. And they begin growing as well.

Tom once again starts to hone his architectural talent. Summer begins to reexamine her antipathy toward commitment. Baby steps toward permanency.

Just how the relationship gets better or worse, maybe better again and perhaps worse again, is what “(500) Days of Summer” is all about. It’s about how and why relationships survive and how or why they sometimes don’t. There’s no good guy, no bad guy here, just two people attempting to discover if love exists.

The catch? We’re taking on Tom and Summer’s journey in a somewhat nonlinear fashion, a clever integration of good times and bad times, of popping into (and out of) the couple’s expectations. Also cleverly imposed: a splitscreen glimpse of expectation versus reality, a what-if scenario viewed simultaneously through rose-colored glasses and the harsh light of reality.

There’s even a bluebird of happiness.

Folks in the biz are calling “(500) Days of Summer” a post modern love story. Meaning Rock Hudson and Doris Day wouldn’t recognize it. Meaning it’s time to throw all those traditional views of cinematic love out the window.

It’s distributed by Fox Searchlight (“Little Miss Sunshine,” “Juno,” “Waitress” and the upcoming “Adam”—films that don’t portend the ordinary.) Meaning if you’re yawning into the face of all those seasonal blockbusters, maybe it’s time to spend a little summer with Summer.