Many years ago I had a newly married friend  whose pride and joy was his MGB Roadster sports car.  It had been “round the clock” once, never let him down, but was looking aged.

After a routine service the local mechanic, Murdo McDoomster, warned him that before long it would fail.  He’d be stranded on the hard-shoulder of the M1 and likely as not flattened by a truck.

Something had to be done.  A fatal accident was unlikely.  Much more probable was the car failing to start one morning and an important meeting being missed.

A new sports car was one option.  Mr Galileo – a local dealer – had tried enthusiastically to sell him one. It was very shiny on the outside but there were rumours of reliability issues.

“But it hardly does any more than the car I’ve got”, my friend had said.  “It’s just newer”.

“It’s not just about the car, it’s the lifestyle that goes with it”, was the reply.

“Well I’d certainly be late for a meeting in this car – the dashboard clock shows the wrong time”.

Despondent, my friend had stopped at a local newsagent.  There was a card in the window.  “Van for sale. £500.  Good runner.  Contact Eli Rahn on STANAG 4373.”

Maybe he could buy a van as a back-up?  It would be a quick fix.  He finally consulted his wife.

“I could buy a new sports car from Mr Galileo.”

“Of course.  But in the next few years we might start a family.  Life moves on.  Maybe those days are over”, she said.

“I could buy Eli Rahn’s van as a back-up”.

“Just remember, you’re surrounded by people trying to sell you what they’ve got.  You’ll have to work out what we really need and go and buy it.  It’ll cost money.  But do it sooner rather than later, before you miss that important meeting”.

My friend wasn’t good at making decisions.  Luckily, that night, a hoard of little gnomes in pointy hats and boiler suits appeared in his garage and remade his MBG Roadster with magic parts so it never broke down again.

The moral?  There’s no avoiding decisions, be they to do with changing cars or tackling GNSS resilience.  And do the sums properly.  Don’t rely on metaphors or magic.