My dad was a policeman, uniform not plainclothes.

So, what’s the difference between the two?

Well, as Dad explained it to me, uniform police are there to prevent crime before it happens, plainclothes are there to investigate crime after it’s happened.

Dad had a mantra which he often repeated to me: “An ounce of prevention is worth a pound of cure.”

If you thought about things before they happened, you could avoid a lot of problems.

This led to his other mantra: “Use your loaf.”

(Loaf being rhyming slang for ‘loaf-of-bread’ – head.)

Both were good mnemonics, which is why they’re stuck in my mind decades after I first heard them.

I learned another good mnemonic from my Uncle Reg.

He was a fireman, and one day he saw me climbing a ladder holding the sides.

He said “Don’t climb like that, lad, that’s how builders climb.  Climb it like a fireman: hold onto the rungs not the sides.”

He explained that where firemen climb there are flames and debris, but the real danger is all the water from the hoses.

The water makes the ladder slippery and if you slip you could fall if you’re only holding the sides, but if you’re holding onto the rungs you’ve got something to grip.

That was another great mnemonic that stuck with me over the years.

Because a mnemonic is a powerful device to make you remember something.

Something that stays in your memory after everything else has gone.

What’s left is the residual communication.

For us, residual communication is the most important part.

It’s no good having a nice piece of body copy if no one reads the ad.

If they look at the visual and turn the page, the residual communication will be the visual.

So having all your selling points in the body copy won’t mean anything.

Residual communication means the mind links whatever it remembers to the nearest, most salient category or brand.

For instance, I saw an ad the other night with a giant chicken walking through a restaurant.

It was well shot, the visual was strong and funny, but I couldn’t remember who it was for. If you’d asked me I’d have said: “Chicken plus restaurant: must be KFC or Nando’s”.

So that’s who I remembered it as an ad for.

Because the chicken was the most powerful thing in the ad, so that was the residual communication.

But I looked up the ad and I was wrong, it wasn’t for KFC or Nando’s.

As the massive chicken walks through the restaurant, this is what the VO says:

“This is Debbie’s nightmare.

Losing track of her invoices has led to an unexpected visit from her suppliers.

But this is merely a figment of her unwoken imagination.

With Intuit QuickBooks, Debbie could see her finances in real time, so there’s no surprises.”

Effectively, the VO was like body copy and the chicken was the powerful visual.

The commercial was well-shot and funny, but the VO was overpowered by the strong, visual idea.

Consequently, I remembered what was impactful – the chicken.

And, in remembering the chicken, I attributed the ad to the wrong category.

That’s why the most powerful element  needs to link it to whatever you’re selling.

I think a lot of people make that mistake, if we don’t consider the residual communication we have no control over it.

The most powerful part will be what’s remembered, and that may not be what we wanted.