Metaphors are
fossils,
language is fossilised metaphor.
As far as I can remember, I absorbed the meanings of figures of speech in the same way that I absorbed the meanings of words. Stick meant a piece of tree, droob didn't. Putting the cart before the horse meant doing things in the wrong order, putting the duck before the wheelbarrow didn't. I may have been told that they had carts and horses to drive before cars were invented. But we don't think about that when using the expression.
Most figures of speech are fossils, divorced from everyday meaning, dead islands of implied activity. Those that aren’t yet, will be if they last.
It's possible that when visiting the supermarket, you do still put all of your pre-packaged eggs in one shopping basket, then put the accelerator pedal to the artificial fibre carpet the covers the metal on the way back to your home where all the tacky, outmoded china ducks are in a row over the fireplace. Maybe then you will stare at the microwave, waiting for your water to heat.
But when was the last time that you had a literal long row to hoe? Do you know anyone who has separated their sheep from their goats recently? Have you ever been faced with the choice of which to put first, the carriage or the draft animal? Ever preached to the choir or timed the shakes of a lamb’s tail? Have you had too many irons in the fire lately? Have you ever counted eggs, in order to estimate the number of hatchlings that will result? For this last one, my mother quite literally did it when she was young and on the farm.
The meanings of these metaphors were once obvious as it drew from everyday experience. Now they are just the fossil casts of prior habits. They are memorised, and yet it doesn’t seem to make much difference.
One day, your grandchild may ask you "gramps, why do they say 'put the pedal to the metal'?" and you will say "Well squirt, when I was your age we has to drive our cars by hand. And foot too."
Most of language is based on metaphor. For instance, the word 'metaphor' means 'to carry across'. Carrying across being a spatial metaphor for cognition. 'Based on' is another spatial metaphor, as though thinking were a building. Once you start looking for metaphors, you'll see them everywhere (Metaphorically speaking of course. You can do it with your eyes closed). A good metaphor is a brick on the accelerator pedal of language.
Wick adds that All of language is based upon metaphor, as is any semiotic system. Words are fossils too.