My father was a strict person. The son of a Huddersfield school canteen cook, he personified the so-called strong, silent type — a real-world Rooster Cogburn. Peter was complicated. He was belligerent by nature, radiating ruthlessness beneath his affable surface. I never saw him cry, even in those last painful days when pancreatic cancer turned him into a thin memory of his former self. The closest I got was when he regularly picked up a little black notebook and crossed out something with a red marker. When he died, I found the book and opened it. He had crossed out the names of all his dead friends. Of the 100 or so names, only a few survived what he morbidly called the kill list.

I’ve been thinking about my father lately, especially about the nature and beauty of friendship. There is an inexplicable connection to people with whom you share no biological connection or sexual attraction but are woven into your life story, to the point where it becomes almost impossible to imagine life without them. As Aristotle remarked, “A friend is one soul abiding in two bodies.”

Eros begins to lose the battle with Thanatos. Death anxiety spreads

One of the most profound friendships of my life ended suddenly and tragically. Phil, (aka Duggy), who was my best friend since leaving high school, with whom I shared so much and whom my mother regarded as a second son, died suddenly of a brain aneurysm.

His death impacted me deeply, and the time I spent with him will always be remembered. He was a true friend. Like all good friends, he was someone I could share special moments with. From late-night drinking sessions to crowd surfing and dropping acid, I did it all with that spiky-haired vegan. I’ll never forget the night we crashed a wedding party because we had run out of money for the night. We stood outside drunk for hours trying to remember our backstory in case we got caught. He picked me up when he found out a girl I was dating was cheating on me, and I needed his support. In the words of noted social anthropologist Taylor Swift, it’s nice to have a friend.

What is the magic number for having friends? Is it Dunbar’s number? Named after the Oxford evolutionary psychologist Robin Dunbar, the theory posits that human beings have five close friendships and up to 150 meaningful relationships.

This is dependent on your age. When you’re young, there’s a certain naiveté. In adolescence, you find yourself in a whole new world of thousands of relationships, without the wisdom of experience to know that many of them will fade almost as quickly as they begin. As we leave high school, we sign each other’s shirts, exchange numbers and vow to stay in touch.

As we approach middle age, we find ourselves entering into an unwanted relationship. Eros begins to lose the battle with Thanatos. Death anxiety spreads. Whatever we do to avoid it, such as developing a cocaine habit or buying a Harley-Davidson, existential dread seeps in. As Martin Amis put it, “Your youth evaporates in your early 40s when you look in the mirror. And then it becomes a full-time job pretending you’re not going to die, and then you accept that you’ll die.”

Whilst spouses and partners generally become de facto best friends, we drift away from some relationships. Whether it’s children, physical distance, or beliefs and opinions, many people will disappear from your life. Case in point: five years of friendship ended abruptly when an ex-friend told me they couldn’t be friends with a conservative. That was news for this writer, who generally votes for the moderate Social Democrat Party.

To build a friendship with someone, you have to establish trust. This requires a great deal of emotional investment — a commodity that diminishes significantly with age. As my friends disappeared and, in some cases, passed away, I began to understand why my father sighed deeply every time he picked up that book.

Like the ink on my old school shirt, memories are starting to fade

As a pre-internet child, my collection of memories is stored in my head and photo albums, not on the cloud. Like the ink on my old school shirt, many of those memories are starting to fade.

Advances in technology have made it easier to communicate with others, but it comes at a price. Social media has reduced friendship to an abstract value. For some people, their friends list is just a number — something to permanently obsess about. Living vicariously through the life of a stranger is not a healthy way to live. Followers are not necessarily friends.

Almost one in ten Britons say they have no friends at all. This can be improved during your younger years, but it becomes increasingly difficult to make friends as you get older. The data suggests a link between loneliness and suicidal ideation. Because middle-aged men and women are more likely to die by suicide than any other age group, we should try to spend more time with others. Contrary to what lockdown enthusiasts think, social isolation can be deadly.

True friendship is more than the typical greeting card cliché or vapid message from a new age life coach. It is an unwritten contract of loyalty and commitment — a tacit agreement to accept the character and behaviour of others and all that entails. Like the best things in life, it can get better with age. Research shows that knowing you have someone to confide in can boost your self-confidence and self-esteem and might even save your life. Thomas Aquinas was right. “There is nothing on this earth more to be prized than true friendship.”