This worthwhile movie is psychological, and must be approached psychologically if it is to be fully appreciated.
Nina tells us that it is most important for her husband to be Prince Charming. She was raised in abject poverty. Yearning for a rescuing prince shaped her personality from the beginning. She is a good person in a good marriage with little income (as in her childhood), but is drawn into an affair because she experiences Sergei, a rich banker twice her age, as Prince Charming. Her irresistible attraction to Sergei is not love, it is years of pent-up yearning for a rescuing prince. For Sergei, the affair is all about sex with a submissive woman with no strings attached. For Nina, the affair is all about uniting with Prince Charming, sex being one vehicle to indulge her deepest desire for union with a powerful prince. For her the affair is prince & princess, it is emotional; for Sergei it is stud & mistress, it is physical. Neither she nor Sergei has a clue about what motivates the other, and Nina understands nothing about the all-consuming love that captivates her. There is no common motivation. This sets the stage for disaster.
Nina's behavior becomes bizarre, she even stalks Sergei. Their affair is prolonged by Sergei's sense of responsibility ("I don't want to, but I have to."). His material support after leaving husband Sasha allows her to continue her Prince Charming fantasy long after Sergei intentionally tries to get rid of her (at one point he refers to her as stubborn). Sergei ignores her to the point of rejection and she lives alone without friends. Her ability to tolerate virtual solitary confinement and still be totally consumed by love is a good measure of the strength of her prince fixation. She acknowledges that Sergei treats her badly, but says there is nothing she can do to change her love. But there is something he can do. Her imaginary world is shattered only when Sergei expresses no joy over her pregnancy and rejects parenting their child. With this unpardonable betrayal by her prince, now-cynical Nina goes to the opposite extreme, declaring total independence while rejecting love as a disease (which is correct in her case). A major weakness of the film for me is that it doesn't show anything about her transition from prince to non-prince. With the persuasion of Sergei's wife, the affair proceeds into marriage, but without the prince delusion and against Sergei's will. There is no joy and no emotion in this marriage, there is nothing beyond a contract and a baby.
The final scene. Nina arranges a rendezvous with ex-husband Sasha. It is intensely emotional with only implied eroticism. Sasha declares his love, Nina bares her soul. The suffering of an innocent heart betrayed from within and without is palpable. If you examine this scene closely you will see many indications of inevitable return to Sasha, whose love for Nina knows no bounds. Nina hasn't experienced such emotion in a very long time. She leaves the hotel looking as if she is on her way to jail. Nina has begun to appreciate Sasha, her real Prince Charming.
This movie examines one of the psychological underpinnings of romantic choice and its potential for pathological consequences both consciously and subconsciously. Filling psychological fixations with good relationships is essential for emotional growth, it allows us to heal and move on. Despairing Nina is not a lost soul. If she can resolve her Prince Charming fixation and its residue, and replace it mentally with a male ideal that can exist in the real world, then she can have a safe, mature relationship. She knows she can rely on Sasha's love and she can afford a battery of therapists, and Sergei wants out. She initiated their rendezvous. Her chances are good.
There are just a few movies that reach deep into the mind and give insight into the hidden causes of our behavior. By showing us how and why we think, they help put us in control and make us more tolerant of others and ourselves. These movies tend to be mysterious and often quite artistic. This is creating art for the highest purpose. The tension at the end of About Love really needs to be resolved. Earlier in the film Nina was suspended in a state of faux love, at the end she is suspended in a state of anti-love. Only half the lesson has been taught. This cast, with scripts co-authored by therapists, could provide a huge service and a very good movie about Nina's road back home. An anti-dote to silliness and the social damage done by pervasive film violence.