There’s this: I’m still alive. That may sound a rather dour way to begin a reflection on the first forty years of my life but, in fact, my survival was never assured. In 2003 I almost died in a car accident, which removed my sense of smell, some of my nerve function and hearing, and a good deal of my fear.

This was a defining moment in my life but not in the way many have imagined. I never experienced a renewed intention to suck the juices from what existence had to offer. I also never developed a terror of driving, or a new respect for road safety. But it did somehow make me feel a little more invincible. If I could survive that, I could survive anything.

I loved my thirties. Which considering this inciting incident may seem strange. They also contained a veritable shopping list of other personal tragedies as mild as failed investments, and as searing as divorce. But being in love, if you can hold that memory through its opposite, changes you for the better. And permanently. Giving love and fighting for it is one of life’s most noble quests, regardless of the outcome.

And then there is my business – the complex, thriving, striving world of an ad agency, which for me is tied with a single thread back to the first business I founded in 1995. Nothing I ever learned or heard about could have prepared me for what this thing has become: for all its imperfections, a fine entrant in an industry that has changed the world. My greatest learning, though, is this: find people you can love and admire, and stick with them. There is no other business secret worth knowing.

Ageing is strange because it is relentless and non-negotiable. As I lift dumbbells I could never have managed in my twenties I am yet constantly reminded of the futility of trying to keep my body young. Words come less quickly than they used to. I get tired more easily. When I look in the mirror I see grey hairs and wrinkles, still, thankfully, in the minority but their march toward dominance has begun.

Cliches abound. Everything you’ve ever heard about getting older, old even, is true. You gain experience but you lose vitality. You resent youth for its rubbery ability to bounce back from anything, but you don’t envy its insecurity. You have more money but less time to spend it. And if you have no children, as I don’t, you worry that you never will.

You look back on the certainty you had when you were eighteen and you laugh. As I now know I will look back at sixty and laugh at myself now.

I have never believed the admonition to live each day like its your last. That may lead to a life of hedonistic pleasure and excitement but you lose periods of tranquility, and you never put down roots. Change is a thrill but it pays diminishing rewards as you get older. As with all wisdom this is a lesson young people need to learn the hard way,

But on turning forty one must pause to consider that life is finite. And that some of things I have not done I will now never do. I will have to live these vicariously through other’s stories. But how fortunate to live at the most connected and information-rich time in human history. All experiences are a few hyperlinks away – or at least a good, long sip of them is.

I celebrate my good health and the opportunities that abound in my life; newfound love and a richness of smart, talented people that I get to interact with every day. And I also celebrate my memories. I have always been a nostalgic bastard, but turning forty threatens to turn me downright sentimental.