My wife looked at me. 'I don't know why you have a long face,' she said. 'Do some kind of analysis or something.' With that she was back inside the changing room and I was left on my own again in fashion purgatory.
Bitter experience had taught me that, had I wandered off, it would have been at the precise moment that I was summoned to provide an opinion or a different size. So I stood and sulked.
Then I saw him. The epitome of teenage angst. Pierced, pointy and filled with the unmissable insolence that only erupts in the final stage of adolescence. As he passed I noticed, with an odd flash of recognition, what he was about to try on. As unmistakable as they were unlikely, my youthful friend was carrying a pair of Levi's 501s.
For men of a certain age, 501 jeans retain a special place in our collective fashion consciousness. A quarter of a century ago, 501s were the height of cool. They were Eddie Kidd with a quiff, Nick Kamen in his boxers. They were male sexuality set to a Motown beat. If there was a secret combination that unlocked the 80s for teenage boys, it was the numbers five, zero and one.
Yet here was a lad, who wasn't even born back then, clutching a pair like they were the hottest thing in the shop. Someone had to tell him about the inglorious events of the 90s and how 501s lost their way. About how those pert young bottoms, which had slipped so effortlessly into the soft blue cotton, had started to sag and enlarge. About the aging process that turned once-lithe boys into fat, boring men. About how these men stayed loyal to 501s, and that brand loyalty became Levi's undoing.
As their waists grew and their fashion sense shrank, these, now middle-aged, men continued to squeeze themselves into their favourite blue jeans. Slowly, the brand equity of 501s changed.
Out went youth, sex and cool to be replaced by flaccid, aged mediocrity. Just as 501s had launched Levi's resurgence in the 80s, the style's creeping gentrification ensured a marketing disaster for the jeans brand, which was subsequently enveloped by the long, dark night of fashion death.
However, the dawn must come round at last. A generation of teenagers has now burst its way into adulthood knowing little or nothing of the history of 501s. Meanwhile, after much prodding from their wives, the majority of middle-aged men have finally laid their 501s to rest and moved on to easy-fitting slacks and the occasional pair of sweatpants. A demographic firewall has been created.
Thus, at the precise moment that 501s went completely out of fashion, they started their irrevocable return to the centre. A new generation of boys will discover the jeans, and once again, middle-aged men will gaze wistfully at the scarlet tab on bright blue denim and recall times long past.
Marketers should treat this as a lesson on the eternally recursive nature of this thing we call fashion. I would also invite gentlemen in their middle years to join me on a journey to the deepest, darkest corner of their wardrobes. Unearth your oldest and most ancient item - that last remaining pair of 501s. They are now the coolest thing you own.
Bring them out into the light and take a long, deep breath. Let your mind and your waist remember a better, younger you. Dip your feet back into the cotton of the past, and let your pelvis slide gently into the familiar folds of an old friend. The jeans are back. Unlike the men who wore them well so many years ago, they can be cool again.
30 Seconds On...Levi's 501 Jeans
* Levi Strauss was a German trader who moved to San Francisco following the California Gold Rush.
* He met Jacob Davis, a tailor, and together they invented a method for reinforcing the weak points of work pants with metal rivets. The new product was patented in 1873 and the company assigned it the number 501.
* In 1985, Bartle Bogle Hegarty rode the wave of 50s nostalgia by having model Nick Kamen take off his 501s and wash them in a laundrette, with Marvin Gaye's I Heard it Through the Grapevine as a soundtrack.
* As a result of the ad, sales of 501s shot up 800%. By 1987, sales of Levi's jeans were 20 times what they had been just three years earlier.
* The commercial also boosted sales of boxer shorts, even though Kamen only wore the iconic white boxers in the ad because he was not allowed to appear in jockeys.
* Levi's sales reached a peak of $7bn in 1996, but have been in decline ever since. Yet, there are signs that the brand may be on the way back.
Sponsored By: The Brand Positioning Workshop