Did you ever wonder where this odd expression comes from? Why would gravy be associated with having an easy time of it? And where does the train fit into it?
The earliest records of the phrase are from the early 20th century, and seems to have come from railroad workers, who would refer to an easy assignment as being on the gravy train. It quickly caught on and came to be used in everyday English.
All well and good, but that doesn’t really explain anything. Looking a little deeper, it seems that the word gravy had already been used for some time to mean something good and easily gained, particularly money. It’s not exactly clear where this meaning came from, but it’s probably a pretty simple use of the concept of gravy being a tasty little bonus to make a meal even nicer. That might seem a little odd to us now, in the 21st century, when gravy is readily available on every street corner or newsstand, but back in the day, gravy wasn’t always guaranteed, so it could be a pleasant, tasty surprise when your dinner was served with it.
With that in mind then, it’s not too unusual that railroad workers would come up with the idea of a gravy train. What’s interesting to me is the fact that we still use it today, long after we’ve lost sight of its origin. It’s a memorable image, I suppose, which sticks in your mind quite easily. And moreoever, it’s unusual. It doesn’t quite make sense, and maybe that’s why we’ve continued to use it. It mystifies us, even if we don’t consciously think about it, and maybe that’s what keeps it in our minds.
Except now you know where it comes from, so you’ll probably forget it. Sorry.