I read the thread by RRose. "Catch 22" is a phrase that has gained its meaning from the book by the same title, based on its plot. Are there any other phrases like that, that have gotten their meanings due to an event in history or occurance?
In the US during the 1980s, there was a sudden rash of disgruntled post office employees going to work with a gun and shooting their superiors and co-workers. Luckily, that has happened in a long time, but we still use the phrase "going postal" to describe someone who suddenly goes on a rampage or has a fit of bad temper.
"I'd better not be late for dinner again or my mom will go postal on me!"
In the UK, if you're 'on Carey Street', you are bankrupt or heavily in debt. This is because Carey Street is where the bankrupcy courts are. We talk about the 'man on the Clapham Omnibus', meaning an ordinary person, and this phrase was used in a famous court case.