Dante said it best - at the midpoint on the journey of life, I found myself in a dark forest for the clear path was lost. In my case, it was the Westfield branch of the preppy clothes shop Hollister.
I'd gone in with my daughters and they'd vanished into the gloom. All around me angular, coltish and lithe young people drifted as if caught in a breeze. The music throbbed. I saw my youngest daughter...
"It's too dark and too noisy, and I can't see anything," I mewed - and time briefly stopped.
Had I really said that? I, who stumbled around the podium at the Ministry of Sound? I, who stage-dived at a Guana Batz gig? I, who actually paid good money for 23 Skidoo's catastrophically unsuccessful industrial clanking album The Culling Is Coming? Too loud? Who am I?
I'm in the vanguard of Generation X - born two years after it mooched into troubled existence in 1965, the very year psychologist Elliot Jacques first coined the term "midlife crisis". I've had insane haircuts, been in noise bands, run club nights in dodgy venues, travelled to wasted war zones with the risk of chemical attack and equally wasted after-party parties. But on my last birthday, I hit that number. The big one. The tombstone of dreams. And until then, I'd been surfing this whole growing-up thing. Then suddenly I started panicking.
Looking around me, I can see I'm not alone. Presenter Chris Evans's recently published book Call the Midlife was a confident advice guide on facing the big Five-Oh, which sounded convincing right up until the moment he quit Top Gear. Social commentator Miranda Sawyer has just released her midlife memoir, Out of Time. Ben Stiller - whose film Reality Bites defined the Gen X grunge aesthetic - has just starred in Walter Mitty, about a middle-aged man's fantasy life. Michelle Obama claimed her controversial 49th birthday fringe cut was a midlife crisis: "I couldn't get a sports car. They won't let me bungee jump..."
But Generation X - growing up under the threat of nuclear war, facing the first wave of advertising that sold a lifestyle and not a product - we've always been quite precious about avoiding cliche. And an X-er midlife crisis is a very different thing to the type that our parents had.
"The Boomer's midlife crisis - having affairs, buying motorbikes, quitting their job to become an artist - all came from financial stability," argues Bill Hodson, a music industry executive in his late forties. "We're not in a position to keep mistresses in Soho flats and ride around on Harley-Davidsons. We're the generation who would boast about going out Friday night and being found still dancing on Monday morning. Unfortunately, those life choices turned out to be disastrous - leeching out our serotonin and playing merry hell with our joints.
"We're not looking for an exciting, creative career change," he says, "we're just hoping we can hang on to our job or keep our business going for the next 10 years."
For Miranda Sawyer, "I realised I was having a midlife crisis when I started doing the 'death maths'. That moment when you realise you've got less time ahead of you than the time behind you. But for my generation, we're finding ourselves here without the products or big houses we might have expected."
So what does a Generation X midlife crisis look like? It's not hard to find out. We are the first generation to have our midlife crisis smeared all over Facebook. That's where you'll see the Glastonbury pics and the fortysomething Mamils (middle-aged men in Lycra) on their carbon-fibre bikes (the new Porsche) going on day-long road races (the new gold - a whole day away from the family). It's where you see the fastest-growing group of problem drinkers (middle-aged mums) sharing snaps of mid-week group outings that make stag nights look tame.
For a morose, self-obsessed and deeply ironic generation, this is a bit of a dilemma. "Social media is the worst possible thing for a midife crisis," explains Sawyer, who keeps trying to come off Facebook. "Everyone's just posting the edited good version of themselves - great holiday, great exam results, love their partners. It makes your failures seem more of a failure. Sure, this is all a first world problem. But I live in the first world, and giving up on your dreams hurts wherever you are."
The real tragedy for midlife X-ers is that command and control seems to have passed from Boomers to the Millennials and Gen Z without giving us a shot (yep, Gen Z. Already. Or iGen. So let's stick with Z). When we were kids, our parents would drive us to the pub and let us play in the car park while they got drunk and threw us the occasional Coke and crisps. By the time we had kids, we had to drive around for 20 minutes trying to find a family-friendly pub with a children's menu, then spend the afternoon chasing six-year-olds up and down the plastic slide in what used to be the beer garden. We never got to choose the pub. Although maybe that's a good thing.
"The reason we're leaving the EU is basically down to a typical Gen X midlife crisis," argues Adrian Denholm, who runs an advertising research agency. "Cameron had all the anxiety and inability to take control that characterises Generation X, so he outsourced it and completely messed up what he wanted. We should never be given responsibility. We're not up to the job."
I've avoided the carbon-fibre bike, but have fallen victim to something a little stupider - signing up for a Tough Mudder assault course obstacle race that is clearly unsuitable for a man of my advancing years. Plus I've joined a band. Again. And played bongos on stage in Croydon on an up-and-coming bill that mainly consisted of angry white rappers. The brief middle-aged bossa nova set went down as well as you'd expect.
And then there's the Hollister T-shirt. If I'm honest, I mainly bought it because, in the simmering half-light of the store, I couldn't see my reflection in the mirror - so I yelled at one of the dewy-eyed 19-year-old catwalk models who work there: "How does this look?" "Great," she said. "That's really working for you." Proving that no matter which generation a man is from, he'll literally do anything if a young, attractive woman says it's a good idea. There may be trouble ahead...
• You notice time ticking by
• Feel crushed by the same old boring job and partner
• Reinvent yourself with clothes, hair, cars and arts/crafts
• Tell younger generation they don't know how to rock
• Wonder how Mick Jagger's hips are still working
• You notice time ticking by
• Feel crushed by existential meaningless of existence
• Reinvent your midlife crisis so as not to be like goddam Boomers
• Tell younger generation they're too smug
• Wonder how to stay awake long enough to go clubbing again
• You notice time ticking by
• Feel crushed by patronising older generations
• Reinvent the workplace to confuse them
• Tell younger generation they'll never get a job
• Wonder how Snapchat actually works