Once a metaphor takes on its own life ... the linguistic specifics of its original conjuring then take a back shelf to its new semantic life

How true, W'ON. Another twist on this phenomenon: expressions which enter the language which are not true to the original.

A famous example: Winston Churchill is remembered for saying "I have nothing to offer but blood, sweat and tears" but he actually said:

"I have nothing to offer but blood, toil, tears, and sweat."

When we accuse someone of "gilding the lily", we think we are quoting Shakespeare. But Shakespeare wrote "To gild refined gold, to paint the lily".

Invariably, the mis-quotation which enters the language is an improvement on the original.

How much of a literary giant's reputation is owed to a rogue editor, I wonder?