You’ve heard the catchwords your mileage may vary (YMMV) hundreds, if not thousands of times. YMMV began life as a small print (or quickly spoken) disclaimer, tacked onto the end of an automotive advertisement.
Perhaps William Safire could pin down the first usage of “your mileage may vary,” but it’s likely to have happened shortly after (or maybe when, but most likely not before) the Environmental Protection Agency (EPA) began testing the fuel efficiency of automobiles sold in the United States in the late 1970s and early 1980s. The subsequent popularization is a thing of legend.
YMMV … It’s obvious when you sit down and think about it.
