I DON’T think CS Lewis was entirely correct when he wrote “Friendship is unnecessary, like philosophy, like art. It has no survival value.” That would be to suggest, for example, that enlightenment, beauty or music can’t elevate a mood. But he was right when he said: “Rather, friendship is one of those things that give value to survival.”

The subject is on my mind after a long weekend spent in Malaga with seven old friends. Initially, I was a reluctant traveller; a mix of too much to contend with at home and feeling a little less commonality with those who can drink (way) so much more.

But I was wrong. Not about the drink, but in forgetting the effect of having friends around.

Here’s an example; at the town square on Sunday, with burny hot sunshine beating down and the locals at home siesta-ing, a Spanish couple arrived with a boom box, played loud salsa music and danced. And no sooner had the Cuban beat hit in our ear drums than Big John Campbell had hit the square tiles and began revealing some quite outstanding salsa steps, some sexy hip swivels and perfect arm extensions (especially for a Baloo-sized fella.)

The less-than-tiny dancer was in his element (we learned later he’d had a couple of lessons) yet more importantly, JC began calling upon passers-by to join in. And they did. Five minutes later, he had 50 or 60 tourists imitating his hip moves and we realised he’d been instrumental in creating a flashmob.

But Big John’s moves were important for another reason. He reminded us that we all begin by dancing alone, we come from a place of solitude, but gradually with friends we fall into step – which helps form human character. The weekend was a conga of such moments, of fun, teasing, empathy and for the happiest dancers amongst us to bring the others into line.

It’s vitally important we dance with friends, according to a new report from the Institute for Fiscal Studies, because it reveals the middle-aged are increasingly likely to die “deaths of despair” (from suicide and alcohol abuse). And one of the principal reasons is loneliness. To underline the report, figures from The Office for National Statistics in 2017 – the latest available – showed the highest rate of suicides was among men aged between 45 and 59.

But what are true friends? How do you make a distinction from acquaintances? The question was thrown at me recently during a bar room conversation when I’d mentioned the name of a showbiz pal. “You’re deluded!” said my accuser, with all the zeal of a procurator fiscal. Then he warned: “He’s not your pal. He’s an acquaintance.”

However, I’ve long worked out the difference. A friend is someone who calls you even when you haven’t rung them for a while. It’s someone who pushes you to come on holiday. It’s someone who Likes your Facebook post, even if it’s not that funny. It’s someone you once had a relationship with, and even though that didn’t work out, still wants to connect because it would be crazy not to.

A friend is someone who takes your calls after curfew time, who listens to your saddest tale even when it involves someone who’s not their friend, and is prepared to ask all the right questions.

A friend is someone who shares their own traumas, asks for your thoughts. A friend is someone who can make you a better version of yourself, because they know you better than you do. A friend is someone who could put a trained psychotherapist out of a job.

Friends are the Tom Sawyer to your Huckleberry Finn. They’re Butch to your Sundance, someone who will grab your hand when you go off the cliff, or when facing life’s Mexican guns are still making plans to go to Australia. Friends are a reminder one is a question, two an answer.

But they are also vital to our physical health. Dr Lauren Brent, an evolutionary biologist and professor at the University of Exeter writes that interactions can extend life expectancy and lower chances of heart disease. “When we interact the neurobiological endogenous opioid system [the stuff in our brains that make us feel good] kicks in.”

She explains we’ve long needed friends to help us with social navigation, to tell us where good hunting is to be had, berries are to be found, enemies can be avoided.

Frankie Boyle came up with a nice line which underlines the value of friendship: “Our greatest fear is to die alone, which is why I intend to take quite a few people with me.”

But we won’t always get the chance to shuffle off at the same time as our pals. We may think friends will be with us forever, or at least until it comes time to book the mini-bus to take us to the Lost Cause care home, but that’s not the case. Before you know it, they’re lost to heart attacks, MND, or they’ve fallen off bloody scaffolding.

So go to Malaga. Salsa dance like Big John Campbell. Then pick up the phone to a pal whom you haven’t connected with for a while and enjoy the dopamine surge.

Read more: The seven vodka spirit of Jocky Wilson lives on