The relationships of couples are an effective embodiment of the precariousness of our lives. If we meet someone we haven’t seen for several months, we hesitate to say: “Tell Franco hello from me.” It’s better to find out first, through circumspect questioning, if the relationship with Franco is still on, or if he has been replaced by a Gianni or a Giorgio, because even the most long-term relationships can end suddenly, and no one – today more than in the past – knows the formula for ensuring a marriage will last.

A very old friend of mine, who has been married for exactly 48 years, to a good man, says that in fact there is a formula: you just have to love each other. The problem, she adds in an amused tone, is that loving each other for a lifetime is really arduous.

First, you have to always be attractive to each other, in bed and elsewhere, even if the body is continually changing, even if what first drew you is gone. Second, you have to appreciate not only the virtues of your partner (too easy) but also the vices, especially those that in the beginning were well hidden. Third, you have to constantly demonstrate your great respect for him, even when it’s clear you’ve made a mistake and he doesn’t deserve your respect, because he’s a perfectly normal idiot. Fourth, you have to immediately look the other way when your fidelity is casually repaid with betrayal, and meanwhile hope at least to be betrayed with discretion, just as you will surely do as soon as you observe that being faithful earns you nothing but humiliation. Fifth, you have to repress the desire to break everything and leave, to persuade yourself that the children need a father, even when he’s terrible, that growing old in solitude is far worse than growing old together, and that becoming adult means accepting life as it is – that is to say, repugnant. Sixth, you have to believe, finally, that loving – loving with your feet on the ground, not what you imagined as a girl – is a skilful juggling exercise, a permanent sacrifice, elegantly swallowing a bitter pill.

There, my friend says, laughing, a relationship can last a lifetime. I asked her: has your marriage lasted nearly 50 years because this is what you and your husband did? She answered, annoyed: what do you mean, we’ve been fortunate, we have a strong bond, we love each other deeply. Certainly there are couples who are both happy and stable, and her marriage is of that type – not to be discussed.

So I didn’t discuss it any more. We went back to talking with amusement about couples, betrayals, furtive sex. People always do this, even when we know we’re talking about tragedies equal to a nuclear war. The light smile is useful. It’s an escape route when, for a few seconds, in the stories of others, we get a painful glimpse of our own.

•Translated by Ann Goldstein