[WantonQuantum]

Ahh but that's the point! It's "a universally understood currency" because it has had that status for a long time.

Gold has a status that is different from other metals and other expensive jewellery (e.g., diamonds).

Why gold though? The physical properties of gold make it nice to look at and touch. It's somewhat rare but not too rare (platinum would be a rubbish currency).

So without anyone really thinking about it, gold has become not just something that is valued for itself but something with an established trading value that includes a premium that derives from its status as universally accepted and valued.

That premium derived from its status as universally accepted and valued is exactly the proportion of its value that is the Tinkerbell effect. In a collapsed economy, gold is extremely useful and valuable because everyone agrees that it is.