Most people know the expression "Jumping the shark".
Most people know it means stupid and ridiculous.
But few people know where it comes from.
Happy Days was a TV programme based on the movie American Graffiti: a nostalgic take on 1950s America.
Teenagers hang out in a diner drinking milkshakes, rock and roll playing on a jukebox, hot rods outside, everyone in preppie clothes except for one bad boy.
He was called "Fonzie" or "The Fonz", he wore a leather jacket and drove a motorcycle.
He had a catchphrase: he would hold his hands out, palm up, and say "Heeeyyyyyy".
He became the epitome of cool.
If the jukebox was stuck, he’d hit it and it would start playing.
If tough guys menaced the other kids, he’d snap his fingers and they’d get lost.
Gradually the show became more and more about Fonzie.
His catchphrase became the mandatory feature in every episode.
If the writers were stuck they’d have Fonzie arrive on the scene.
He’d snap his fingers and go "Heeeyyyy" and the audience would laugh.
Season after season the show painted itself into this corner.
The entire show eventually had nothing to do with the original premise of 1950s nostalgia.
Fonzie became the sole focus of the show: the formula.
Each week he would do something extraordinary and go "Heeeyyy".
Eventually, an episode was set on the beach.
Someone dared Fonzie to prove his prowess at waterskiing by jumping over a man-eating shark.
The episode featured Fonzie waterskiing in swimming trunks wearing his leather jacket and dark glasses.
Ages are spent trying to build tension as Fonzie water-skis up to the shark and jumps over it.
This is generally recognised as the moment the show Happy Days ploughed irretrievably into the ground.
When a long, slow decline couldn’t be ignored any longer.
It was so ridiculous it was finally the end.
The show no longer had any bearing on the original reason for its existence.
That’s why, when anything has reached this state, it’s said to have "jumped the shark".
Recently a young creative team was showing me their portfolio.
I didn’t understand a lot of it.
It looked like most of what passes for advertising nowadays.
It consisted of jokes that aren’t actually funny, but are considered witty just by being weird.
Jokes that don’t mention the name of a brand or product and certainly don’t mention a reason to buy it.
I asked the young creative team about this.
They said: "Our creative director said that if anyone understood our ads then they weren’t clever enough".
Now let’s be clear: that’s a creative director explaining the criteria for judging advertising excellence to a young creative team.
I used to think we did advertising for ordinary people.
I used to think the point was ordinary people could understand what we did.
Either I’ve been wrong all these years, or advertising has finally jumped the shark.
Dave Trott is the author of Creative Mischief, Predatory Thinking and One Plus One Equals Three