You are in a bar with your mates and write out little pieces of paper which you give to the barman who is delighted to exchange them for drinks. He is relaxed because he then gives the bits of paper to his bank who sells them to other banks - who just happen to employ the people who are drinking in the bar with you. Everything is fine.

Then the barman finds that his bank no longer likes all the bits of paper he is giving them and starts to say no. First the Spanish and the Irish get no drinks, then the bank doesn’t like any of the bits of paper, soon nobody is getting a drink.

A man called Gordon whips up a posse of his mates and they walk into the bar. Everyone stares at these people, led by a Mario somebody but mainly speaking German and wonders what they are there for. Soon the mystery is solved as Mario steps up to the bar and tells the barman that the little pieces of paper are fine again and he and his pals will exchange as many as the barman wants for real money.

Everything is fantastic again. Drinking and music back on - even Stavros can join in.

After a few days of fun one of Mario’s friends, Luigi, suddenly falls down dead, another, Alfredo goes white and Mario himself starts to look a bit flustered. The barman starts to worry.

This is where we broadly are in the world economy. In 2008 we had a crisis brought on by reckless lending and a belief that liquidity in the banking system would always be there. How wrong we were, central banks had to step in to provide both liquidity and support for asset prices. The result has been the most enormous increase in public debt outside a world war. In 2017 global debt rose by $21 trillion to $237 trillion. These are scary numbers. In the UK public debt is now £1.8 trillion, well over 80% of GDP whereas it was under 40% in 2008; elsewhere in the world the ratio is worse.

What the high levels of debt relative to GDP mean is that Governments do not have the firepower they had in 2008 if there is another crisis now.

Added to this is the massive experiment of Quantitative Easing. Not only is there more debt but much of it is held, not by people who really want it, but by central banks who have bought it to create artificial demand and drive down interest rates. Of the €2.1 trillion of Italian Government debt only about 6% is owned by the private sector, the ECB and Italian central bank each own approaching 20%. This debt is like nuclear waste, locked away and looked after by smart people who hopefully will eventually figure out something sensible to do with it.

Confidence is vital to an orderly unwinding of this distorted position. Without it the man behind the bar will no longer take the promissory notes of his weaker customers. The German public doesn’t yet realise it but it is going to have to shoulder the burden of Italy if the Euro is to survive. Even at its most benign, unwinding QE and normalising interest rates will create headwinds for asset prices - your house, your pension fund, your business.

Three outcomes seem possible. Many years of grind as we work our way to safety, a grab of private wealth by politicians who need to please a restless electorate or much higher inflation. Interesting times ahead. Keep watching Italy. Don’t borrow too much.

Pinstripe is a senior member of Scotland's financial services community.