Late one winter’s night in the mid-1980s, I was making my way home from Hornchurch Station with Thommo and My-Mate-Andy. Inevitably we were chatting about Lloyd Cole and Laughing Brew, fu shoes and The Face. Thommo and I were wearing the heavy tweed overcoats that marked us out as students. My-Mate-Andy was sporting his sheepskin-lined, Forza 12 bleached denim jacket, collar-up. We were high-spirited and a little the worse for wear.

As we progressed down the High Street, a young lad and his girlfriend passed us going in the opposite direction.

Something about us clearly irritated the bloke. We may have given him the impression that our good humour was directed at them. We may have brushed into them, or not created enough space for them to pass. We may have just looked a bit too studenty for that time and place.

In any case, he was not very happy, and in a thrice he became a mad whirring tornado of punches, pokes and prods; ducking in and out of us, throwing fast and furious fists; jabbing and clouting, slapping and bashing. He had turned into the Tasmanian Devil.

Now I’m somewhat ashamed to tell you this. My-Mate-Andy and I quickly recognised that we had met a superior force. There may only have been one of him, and he wasn’t the tallest lad. But we knew we couldn’t compete with the Tasmanian Devil.

And so, setting aside our masculine pride and the deep bonds of friendship, we scarpered in different directions, past bins and down alleyways, off into the cold, dark night.

Thommo meanwhile stood his ground. He took one blow after another. A lightning-fast jab to the left; a lusty upper-cut to the right. Biff! Bang! Pow! Soon his eye was bruised, his nose was bleeding, and his beloved student coat was ripped from end to end.

Eventually the young lad’s girlfriend pleaded for clemency. The Tasmanian Devil stood over the now prone Thommo, paused, took a breath and said:

‘Look. You and your mates have got to learn a lesson. You’ve got to learn one thing: you’ve got to back it up.’

Whilst we never quite established what we had done to upset the Tasmanian Devil, and what precisely we were supposed to be backing up, these words struck me as rather profound. And they haunted me for a good while after that shameful night had passed.

A few years later I entered the world of advertising. I discovered it was a land of hunch and hypothesis, supposition and speculation. And I was myself somewhat inclined to make sweeping generalisations about cultural change; confident conjectures about strategic and brand truths. And yet every time I made such an assertion, I heard a sinister voice, whispering quietly into my ear: ‘You’ve got to back it up.’

And so I would reluctantly reach for the research surveys and category reports. I’d consider commissioning a poll, staging a demonstration. I’d go in search of illustration and evidence. I’d do my damnedest to verify my claims.

Now I’m not saying I ever really became the most rigorous of strategists. But it is true that there’s too much hollow theorising and empty guesswork in our world. And, despite the ubiquity of data, things seem to be getting worse.

If you really want to succeed in this profession, you’ve got to fall in love with proof and validation. You’ve got to befriend supporting evidence and corroborating facts. The Tasmanian Devil was right: you’ve got to back it up.

I recently came across my old tweed overcoat packed away in a box. I tried it on and, remarkably, it still fits. It’s not in too bad a nick, and, with a new button and lining, it could even merit a few outings. I’m not so sure Thommo will be impressed.

No. 173