Seven years ago, my best friend took a sabbatical from work and went to live in Australia for a year. It was among the happiest periods of his life and I envied him the chance to experience good times in Sydney.
But my abiding memory of that 12-month period is one of loss. I missed him greatly, and no number of emails compensated for the fact that we couldn't meet up on a whim, or have a good old bitching session if either of us were having a bad day.
Our friendship was forged in the two years after school when we lived together while studying at the same university and it's remained strong ever since. In fact, it's one of the few constants in the last 20 or so years of my life.
And it's got me thinking about the nature of the friendships men have now that a new study has recommended that we should socialise with at least four other male friends twice a week in order to maintain optimum mental health.
It would seem that very regular contact with male friends would keep us from internalising problems and I can certainly see a lot of truth to it.
But how many married men with a young family and a full-time job can possibly arrange twice-weekly sessions with a group of similarly busy friends?
Not me, certainly. I don't even get to meet up with my best mate nearly as much as I used to.
And with other friends, I have struggled to see them as often as I would like too – and that channel for venting concerns has been blocked. Like many men, I've bottled up worries and prejudices that would have been far better being lanced with a friend over a pint, or as is more often the case with me now, a strong mug of coffee.
That old adage about a trouble shared being a trouble halved is no idle saying – and conversations with male friends over the years have helped give me clarity on work issues, financial concerns and so forth.
When a loved one was going through the horrors of chemotherapy a few years ago, I was glad of one particular friend whose first words to me whenever we met were always "How are you doing?" – four little words that acknowledged that I was suffering too.
That friend is especially empathetic, but even those who are not so attuned to their feelings can work wonders too. Another, by dint of our rantings about football, music and the dire state of Irish politics, always lifts my mood.
The psychologist Allison Keating tells me "men are socialised to be more competitive than co-operative and are not as good at showing vulnerability to each other as women are" but insists that men need each other to share confidences just as much.
"Men can find themselves under enormous pressure. They can help each other," she says.