the penny drops

Said when someone suddenly comes to realize or understand something. Once the penny dropped, I was horrified by my behavior. My mother certainly didn't deserve it. Will the penny ever drop on the urgency of environmental issues? We activists can't save the planet by ourselves! I was watching his expression as he read the will, so I could tell the moment the penny dropped that he had been disinherited by his father.

penny dropped, the

One finally catches on to something. The term alludes to old-time machines in which one deposited a penny to obtain a piece of candy, which one received after the penny dropped all the way down. Dating from the 1950s, it is used more in Britain than in the United States but is still current. Alexander McCall Smith used it in The Right Attitude to Rain (2006): “I think he realises now that she’s never going to come back to him. It’s taken a long time, but the penny has finally dropped.”