John Lawson wrote on Tue, Apr 2, 2002 02:48 AM UTC:
Regarding 'cockles', below. Note that the link actually provides no
solution to the meaning of 'cockles' in this sense. Neither does the
Oxford English Dictionary, which has much the same info as the editor's
link. The upshot is, we don't know what 'cockles' are.
I once read a hypothesis that suggested that expressions that were used
formulaicly, but made no sense (like 'dead as a doornail') were actually
the punchlines of forgotten jokes. Sounds dopey, but think of how many
punchlines you use as metaphors in colloquial conversation, and how often
you really tell the jokes they go with.