The ability to still fancy each other after so many years is an important factor, she adds, as is an appreciation of what each person brings to the relationship. Also, the fact that they have allowed each other a degree of independence.

“I don’t think there’s a secret ingredient,” says Ann, “although I’ve noticed that most successful marriages are between people who met early in their lives. I was 24 when we married.

“This contradicts the popular wisdom that if you have more experience of relationships you’re more likely to make a
wise choice.”

Naturally, their life together has not been without its trials. Ann and Guy hit a difficult patch in 1989 when they invested in an ill-fated music festival and lost a lot of money but they were determined not to let the crisis jeopardise their marriage.

“We come from families with very little record of divorce – for better or worse – and we were mindful to not upset our children who were 10 and 13 at the time. We had recently witnessed a couple of marriage break-ups among friends that resulted in their children suffering a great deal.”

They stuck it out and through their joint hard work survived the testing episode with their relationship intact.

Ann says that within her social circle there are quite a few couples who, like her and Guy, are still in their first marriages and I begin to wonder whether perhaps happy-marrieds attract similar couples as friends, while divorcees also gravitate towards each other.

Val and Robert Chris have been married since 1972. According to Val, their thriving relationship is based on old-fashioned love and commitment, which is what got them through a “rough patch” lasting nearly two decades. The couple live in Tunbridge Wells, Kent, and have two sons.

Robert is a financial consultant and Val is a Blue Badge tour guide but for 18 years in the Eighties and Nineties they owned a bookshop that Val – unwillingly – ran.

“The shop was often a bone of contention,” she says. “Robert had talked me into running it and I felt trapped in a situation not of my making. It was hard work and a huge tie. Running a home, working and having children was exhausting and Robert and I argued a lot. I felt he never gave me enough support.”

She admits that at times she felt like walking away but couldn’t contemplate life without her husband. “By just putting one foot in front of the other we got through it. It sounds corny but I think the longevity of our marriage is due to the simple fact that we love each other. We have always wanted our marriage to work, even when things seemed to be getting out of hand.”

Beyond that, Val believes there are a few vital ingredients: “First of all, communication. It’s important not to have unrealistic expectations of each other and to understand that true love is a lot more than sexual attraction. Other factors are the ability to laugh at yourselves and to be independent without being selfish.”

She muses on why so many marriages end in divorce. “In this age of immediate gratification many don’t have the desire to work out their issues and think the easiest thing is to move on. There’s no social pressure on couples to stay together if they’re unhappy, and maybe some people confuse a passing difficult phase with total incompatibility.

“Then again, perhaps some people don’t make good choices in the first place, marrying for the wrong reasons
without thinking through the implications of spending 40 years with the same person.”

Personally, I think there is an ingredient: instinct. Early in her married life and angry at being left at home while Robert was out with his mates, Val flounced out for a night on the town. She returned very late to find the bathroom full of flowers: “The bath, basin and even the loo were overflowing with them. Robert had defused my rebellion by making me laugh. Not many people use a loo as a vase!”

Robert knew exactly what to do. He didn’t get the answer from a book, he had an instinct for making the marriage work. They’re the lucky ones.