I’ve heard this expression occasionally in British English, apparently meaning that someone of presumably slow intellect has finally understood/ something has finally dawned on someone, etc.
Can anyone tell me the exact meaning and origin of this expression?
Just a wild guess.
It might possibly refer to the old arcade machines, such as one that has a mechanical band of monkeys. The monkeys just sit there staring off into space, until a penny is dropped in, at which point the arcade machine comes to life.
My WAG would be that it would be that it is implying that the brain is like a coin-operated machine, once the penny drops (into the coin box), the machine springs into action.
The penny’s dropped: Sometimes preceded by at last, and often by an exclamatory ah! of satisfaction or relief. It is applied when someone has belatedly realised either what was meant by another’s witticism or, occasionally, the true significance or urgency of a situation. I remember it from the 1920’s, but it probably dates from the very early 20th C.
But this deft catchphrase merits a second comment from a lively mind, ‘At last you understand what I said or meant’ or ‘At last you’ve got the joke.’
From the early penny-in-the-slot machines that needed a jog to make them work. Still current.
Source: A Dictionary of Catchphrases, Eric Partridge.
Can’t tell you the origin but it means the same as, for example, a ‘light bulb moment’ and is not related to a persons intellect.
There are many alternatives. “I just fell in” (presumably of Army origin) being one I hear occasionally – might be just South London but it’s probably in wider use than that.
Another variant is “The light dawns”
Walrus