It started with an extravagant 40th birthday party and ended in a tangled heap of fast cars, unsuitable women and illegal stimulants.
Well, that's not strictly true. It certainly did begin on a balmy and raucous April evening five years ago, when I inexplicably convinced myself that my guests had come to guzzle champagne because they felt sorry for me.
But whether my midlife crisis culminates in the textbook orgiastic mess associated with directionless men in turmoil over their stale existence is yet to be determined.
I doubt it. I've no interest in cars or drugs and am lucky enough to have a gorgeous wife who, it turns out, is the most understanding too.
Because my midlife crisis comes with her (belated) blessing - or at least tacit acceptance that if I'm going to make a mess of things, she won't stand in my way. Well, not until it really gets messy.
It was she who encouraged me to leave my dead-end job with no regrets and launch a media consultancy business from the kitchen table, join a gym and pump iron, write a book and two screenplays at exactly the same time with only vague notions about plot, indulge in a series of ineffectual health food fads and therapists (both leaving me queasy and out of pocket), buy an extra-large wetsuit for Cornish surfing dude weekends and compel me to finish the business plan for a dotcom business which will net us tens of millions.
Like me, she sees the essential truth about the male midlife crisis. It is not something to be ignored but embraced. If approached in the right way, it can be the making of us. The fear of reaching half-time has liberated me, the anguish about where my life was headed has motivated me in ways I never imagined possible, the disillusionment that I wasn't quite who I wanted to be has inspired me.
Which is why women, if not quite endorsing their men's anarchic and pathetic self-indulgence, should welcome it. You're the sensible ones, after all, the Marge Simpson to our buffoonish Homer, the Skyler White to our self-deceiving Walter in Breaking Bad. You're the ones who have the strength to both keep it all together while letting us veer off the rails. And you know far better than us when enough is enough.
Only now do I acknowledge that I fabricated those feelings of worthlessness at my 40th party because I allowed vanity to get the better of me, measuring myself against others in an entirely disproportionate manner. Instead of seeing myself as just, well, Grant the successful journalist with the heaven-sent partner and two perfect children, I was somebody else. A fraud at my own party.
I know now it doesn't make sense and makes me look utterly shallow, but at the time it was the spark that my innate male paranoia needed to set my world ablaze.
We're all teetering on the cliff wondering whether - and becoming increasingly convinced that - we can survive the fall. And instead of trying to suppress the midlife crisis, I'm beginning to feel it's every man's destiny to seize it, and every wife's duty to let him loose.
My far better half sees this childish tantrum - for that's what a midlife crisis is, an immature two-fingered riposte to the humdrum - as a moment that will either eventually persuade me to grow up and re-engage with reality or liberate me to achieve even greater things.
It's brought out the best in me. The consultancy is beginning to thrive, I feel more enthused, my biceps are slightly more impressive than my 13-year-old son's, I have 25 minutes of an Oscar-winner under my belt and I'm starting to enjoy things in a hungrier manner than I used to. But I couldn't have done it without my wife.
Having spent months boring her with my existential angst, she's helped me realise that the key to a midlife crisis is fear - not the fear of failure but the fear of missing out.
I've not carte blanche, though. I reckon another six months before it all starts to turn nasty and she asks for her old husband back - the one with one grip on reality and the other on the ladder up to the boardroom.
Last night at dinner I asked her if she thought Jude Law or Ryan Gosling would be better cast as me in my new tragi-comedy. With a heavy sigh, raised eyebrows and a withering stare, she said: 'Honestly, Grant, how long is this bloody midlife crisis going on for?'