Came across a couple of crackers recently. First, the very-much-alive ‘dead as a doornail’, an expression which:

“… can be traced back to 1350, but could be even older. In the days before screws were commonly used in carpentry, nails secured one piece of wood to another. Unlike screws however, nails could often loosen over a period of time. To prevent this, it became common practice, particularly on large medieval doors, that when a nail was hammered through the wood it would be flattened or clinched on the inside. The process of flattening the nail would mean that the nail would be ‘dead’ as it couldn’t be used again.”

The other – “like cheese at fourpence” – which I hadn’t even come across, being a soft southerner, but which is apparently very much in everyday use in its homeland:

‘…the mill towns of Lancashire, where fourpence was considered expensive for cheese, so cheese at that price would not be bought.’ So, say, a woman whose date failed to show up: “He left me standing there like cheese at fourpence”.”