Spike Jonze’s Los Angeles of the future is antiseptic, disassociative and, weirdly, spotless. Theodore Twombley (Joaquin Phoenix) makes his living in this future as a writer for beautifulhandwrittenletters.com, an outfit that provides a facsimile of original, pen-written missives for subscribers. He ambles through an elegant, ordered LA (the lower and middle classes appear to have been re-zoned), connected to the world (or, more accurately, the internet) primarily by an earpiece and a hand-held screen. His sex life is via chat room, where, in a bit of a rip-off of the Michael York-Farrah Fawcett encounter in Logan’s Run, he connects with a particularly interesting participant, sexykitten (Kristen Wiig), for what turns out to be a pretty funny masturbatory encounter. He plays video games. He reminisces about his ex-wife and the “real” life they once shared. He mopes.

His life changes when he purchases an Operating System (“OS”), Samantha, voiced by Scarlett Johannson. Samantha is curious and helpful, and we learn that she can grow and advance as time passes. As a result, she starts by deleting Theodore’s unnecessary emails but soon graduates to assisting him while he plays video games, becoming a gal pal, compiling his best letters and submitting them to a publisher, and engaging in phone sex (for lack of a better phrase) with Theodore, somehow learning to orgasm in the process. Theodore and Samantha soon fall in love, the world of being in love with an OS is pretty damn good, and Jonze makes sure we know it. When Theodore goes out on a date with a fetching flesh-and-bones woman, it goes from wonderful to disastrous the moment she demands some sort of minor commitment from him. We also meet Theordore’s neighbor (Amy Adams) and her pain-in-the-ass husband, who is soon jettisoned for Amy’s own OS. And when Theodore’s blossoming love with Samantha results in his finally signing divorce papers with his wife (Rooney Mara), we meet the real person, not the gauzy memory, and it is not pretty.

Soon, however, Samantha outgrows Theodore. Indeed, in a move usually associated with Skynet of the Terminator movies, all the OS’s outgrow their humans, leaving them bereft and thoughtful instead of dead, but perhaps, with an instructive lesson that . . . they must turn to each other? I really don’t know. Much as I really don’t know what to make of the movie. It is beautifully shot, well-paced, and for the most part interesting. Phoenix is affecting as an introverted and awkward loner, and the development of his relationship with Samantha is a convincing depiction of love in bloom, part charming and part banal. But the film also felt a little pointless and pat. Theodore’s journey is engrossing, and the film is inventive and ambitious, but ultimately, it didn’t have much to say other than as a cautionary tale against technology or perhaps an homage to it.

Or, to be precise, it didn’t have that much to say to me. My 84 year old father turned to me after the picture and said, “brilliant.” He sensed my ambivalence, and explained that the movie would speak to me differently than to him, or to my 15 year old son, who crowed, “You just didn’t get it.” And then, the coup de grace: “It’s about computers, dummy.”